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View Full Version : The Push For SCSI (or at least Serial ATA)


rice_web
Oct 29, 2002, 09:52 PM
The ONE gripe that I have with "modern" computing concerns hard drive speed. One of the few reasons that applications load slower from one machine to the next is almost entirely due to hard drive speed. So.....

GIVE US SCSI OR GIVE US DEATH (or at least Serial ATA)

SCSI - 15,000 RPMs, BABY
These hard drives are wickedly fast. Seagate has been making 15,000 RPM hard drives for a while now, and have reduced seek times to 3.6ms, and increased transfer rates to roughly 70MBps--nearly as fast as the memory found in the iBook.

Yeah, they're LOUD, but so are the fans in the PowerMac; the difference in noise level would be slight, if any.

Serial ATA
This is a technology that has me excited, even though I know very little about it.

Serial ATA II is due late 2004, but offers transfer rates more than double the current parallel ATA-133 (at least theoretically)

A Dumb Conclusion
If the Mac world really wants something to be proud of, imagine a page file of roughly 10GB that is nearly as fast as the system memory, thus negating the need for 1GB of RAM (which wouldn't hurt).

Yes, processor speeds still need to increase dramatically. Until that happens, Apple should be doing its part to increase performance wherever and whenever possible.

Lz0
Oct 29, 2002, 10:01 PM
Tell me, what's the price on one of these 15000 RPM HDD???

rice_web
Oct 29, 2002, 10:04 PM
Roughly $900 for a 73GB hard drive.... :D

Seriously, though, a 15000RPM hard drive at 36GB would only be $300-$400.

BenderBot1138
Oct 29, 2002, 10:20 PM
I use a 5200 (or is it 5400) 60 GB drive and have no trouble at all collecting live DV straight to my drive. I've seen a post like this here before I'm sure. I think the main conclusion was SPECIFICATIONS. Apple loves em, and so do I.

Conclusion
Bring on those SCUMMY drives if they meet the SPECIFICATIONS. But if I'm not mistaken, ATA is our friend for many reasons that Apple has taken to heart.:D

Chaszmyr
Oct 29, 2002, 10:28 PM
I have a 20gb 15000 rpm SCSI drive from Seagate in my computer... let me tell you, its not that much faster. Unless youre using SCSI RAID you might as well go with IDE RAID over SCSI because its cheaper and faster.

Catfish_Man
Oct 29, 2002, 11:20 PM
...<brandishes rod of techno-death, smites Parallel IDE/ATA and SCSI>. SerialATA, please. For one thing, 15,000rpm SCSI drives are NOISY, for another, they're EXPENSIVE, for another, they're SMALL (in storage space, not physical space). Plus, you've got all the crappy termination issues to deal with, and it's not hot swappable like SerialATA.

Also, if the iBook's memory transfered just over 70MBps, Apple would be long dead. It transfers 800MBps.

SerialATA is hot swappable, small (ever seen how big an Ultra160 SCSI connector is? Mobo space costs money), backwards compatible (driver-wise) with parallel ATA, and has massive industry support. SerialATA has 150MBps max transfer speeds, SerialATAII will have 300MBps, SerialATAIII will have 600MBps. It has most of the advantages of SCSI, without most of the problems. Also, SerialATA kills the annoying Master/Slave issues that current ATA has (with the penalty that it only supports one drive per port, which is not much of a penalty as the small size allows for more of them on one mobo).

Bring on the SerialATA Macs!

g4pismo
Oct 29, 2002, 11:32 PM
My 10k 36g IBM drives can heat my office..My vote is for S-ATA.

szark
Oct 30, 2002, 12:20 AM
I'm holding out for Serial Attached SCSI (http://www.serialattachedscsi.com/index.html) !!! ;)


(By the way, SCSI drives are hot-swappable when using SCA connections)

MacBandit
Oct 30, 2002, 12:21 AM
The IBM 80Gig 7200Rpm drive that came in my new dual has an average transfer rate of 40MB/s. Combine two of these stripe them and you should be able to get somewhere around 75MB/s average. All this speed for less then $300 and you would have a total capacity of 160gigs.

Sorry but SCSI is all but dead with the price and speeds of the modern ATA drives.

Nipsy
Oct 30, 2002, 12:30 AM
As a longtime SCSI holdout, the price performance ratio finally caused me to switch.

I have a 480GB RAID in my machine for $750, which gives me 90MB/s sustained read, and 75MB/s sustained write (4 x IBM 120GXP and a SIIG 133 RAID card).

For about the same price, I could have acheived these speeds with SCSI (2 Cheetahs and a Dual channel U160) card, and had a whopping 36GB to work with.

I still dislike some of the IDE penalties as far as read/write delays, but for anyone who's bothered, SCSI is always a BTO option.

Neither SCSI nor IDE are going to break 50mb/s (sustained) in single drive configurations anway.

It is impossible to justify the costs for consumers, business users, and anyone not dealing with db/video/48 track audio, etc.

IDE is about $1/GB, and SCSI is $10...people already complain that Macs are too expensive.

Notes:

SCSI Drives are always hot-swappable (provided they are in an appropriate carriage).

A dual IDE RAID on one channel will likely give 130-140% performance, because IDE does not process commands in parallel.

A dual SCSI RAID on one channel will usually give 160-170% performance, as SCSI accepts concurrent instructions.

New Seagate Cheetahs 15Ks do run quiet, and cool, but are still very expensive.

Memory round trips are measured in nanoseconds (~10), SCSI seeks start at 3MS, plus the round trip to the drive, so paging to a drive is still 30 times slower than visiting RAM.

MacBandit
Oct 30, 2002, 12:53 AM
Originally posted by Nipsy
As a longtime SCSI holdout, the price performance ratio finally caused me to switch.

I have a 480GB RAID in my machine for $750, which gives me 90MB/s sustained read, and 75MB/s sustained write (4 x IBM 120GXP and a SIIG 133 RAID card).

For about the same price, I could have acheived these speeds with SCSI (2 Cheetahs and a Dual channel U160) card, and had a whopping 36GB to work with.

I still dislike some of the IDE penalties as far as read/write delays, but for anyone who's bothered, SCSI is always a BTO option.

Neither SCSI nor IDE are going to break 50mb/s (sustained) in single drive configurations anway.

It is impossible to justify the costs for consumers, business users, and anyone not dealing with db/video/48 track audio, etc.

IDE is about $1/GB, and SCSI is $10...people already complain that Macs are too expensive.

Notes:

SCSI Drives are always hot-swappable (provided they are in an appropriate carriage).

A dual IDE RAID on one channel will likely give 130-140% performance, because IDE does not process commands in parallel.

A dual SCSI RAID on one channel will usually give 160-170% performance, as SCSI accepts concurrent instructions.

New Seagate Cheetahs 15Ks do run quiet, and cool, but are still very expensive.

Memory round trips are measured in nanoseconds (~10), SCSI seeks start at 3MS, plus the round trip to the drive, so paging to a drive is still 30 times slower than visitung RAM.

Real knowledge is such a great thing. Thanks for the post.

death
Oct 30, 2002, 12:57 AM
every single message on this thread is horribly incorrect

Nipsy gets the award for having only one flaw

Nipsy
Oct 30, 2002, 01:04 AM
Originally posted by death
every single message on this thread is horribly incorrect

Nipsy gets the award for having only one flaw

That being?

MacBandit
Oct 30, 2002, 01:19 AM
Originally posted by Nipsy


That being?

Damn Trolls anyhow. They reach up at you from under the bridge and growl but they don't tell you what about. Explain yourself when you make a post don't just say you were wrong.

After reading Nipsy's post I too realize I had a mistake in my thread. I overated the total possible throughput of a ATA Raid. If you are counting though that is also the only mistake in my post.

death
Oct 30, 2002, 06:59 PM
rice-web: ibook does not go @ 70MB/s, Serial ATA will be released @ 150MB/s, but will not offer increased transfer rates

BenderBot1138: I have no idea what 'specifications' are, Apple uses ATA because it's cheap (no other reason).

Chaszmyr: Yes, it is much faster, you just don't notice it because your computing patterns most likely follow a brief burst of loading and then a long period of interacting with cached data. Additionally, IDE Raid does not help latency and will require over two disks to match a SCSI if both are operating sequentially and at max speed

Catfish Man: SCSI is hot swappable, SCSI is compatible between U2, 160, and 320; that's more than can be said for Parallel -> Serial ATA. Additionally, any OS will have built in drivers for SCSI adaptors. Furthermore, you're just talking about bus speeds, which is pointless. Serial ATA does not have massive industry support, not compared to SCSI and non-serial ATA.

MacBandit: Your IDE hard drive will not get an average of 40 MB/s, even if reading sequentially. SCSI is not dead unless you're cheap and don't care about your data/uptime. Although you might be talking about yourself, if you say that SCSI is dead, you have to face the fact that you are not the world, and SCSI is in no danger from SATA.

Nipsy: SCSI will break 50 MB/sustained, although your math for the RAID array seems right.

Nipsy
Oct 30, 2002, 07:12 PM
Originally posted by death

Nipsy: SCSI will break 50 MB/sustained, although your math for the RAID array seems right.

Agreed, in a RAID config, my old SCSI RAID sat happily at ~215MB/s (PCI Bus saturation) sustained both ways (ATTO Dual U160, 8 Cheetahs).

However, when used as individual drives (which 95% of people are running) did not break 50MB/s sustained either way. The drives were Dec. 2001 Cheetah 18GB drives, and would happily peak at about 45MB/s read, and 40MB/s write (sustained) on the ATTO card.

My point is that people who want Serial ATA or SCSI, and only use one drive don't understand that they won't see a benefit.

A 45MB/s drive will give 45MB/s on a LVD, U160, U320, ATA66, ATA100, ATA133, or serial ATA bus. However, as you add (up to 15) drives to SCSI, you can saturate the SCSI, and even the PCI bus. When you add a drive to ATA, you are unlikely to staurate the bus (ATA133 or PCI) as you can only have 2 ATA drives per channel, and the drives themselves aren't fast enough.

In the future, as drives read more info faster, they will nip at the heels of busses, and busses will grow faster as well, but if you use one drive on a bus, you are msiing the point of faster busses.

avkills
Oct 30, 2002, 08:46 PM
I do not care how you slice it, SCSI whips ATA like nobody's business.

Anyone who needs ultra fast storage has always and will always use SCSI RAID arrays, either using Ultra160, Ultra320 or FibreChannel.

That being said, 90% of most users can happily compute using cheap-o ATA drives. Hell, even I have a 80gb Firewire drive for video for use with my iBook, but if you expect to me to admit it is even close in speed to my 2 Ultra160 drives in my tower, then I also have part of the brooklyn bridge to sell you.

-mark

tjwett
Oct 30, 2002, 10:12 PM
I've used 15,000 RPM fast SCSI drives as well as 10, 000 and they do indeed make a difference with video and audio. Personally I don't think 7200 is enough for these uses unless the drive is very carefully formatted and optimised. SCSI is a must. No shizzle.

MacBandit
Oct 31, 2002, 12:49 AM
Originally posted by death
MacBandit: Your IDE hard drive will not get an average of 40 MB/s, even if reading sequentially. SCSI is not dead unless you're cheap and don't care about your data/uptime. Although you might be talking about yourself, if you say that SCSI is dead, you have to face the fact that you are not the world, and SCSI is in no danger from SATA.

Nipsy: SCSI will break 50 MB/sustained, although your math for the RAID array seems right.


How can you tell me the hard drive in my computer is not able to achieve 40MB/s? Have you been secretly sneeking into my computer room at night and rerunning all the test that I have done that show a read throughput of 40MB/s and a write throuput of 36MB/s?

MacBandit
Oct 31, 2002, 12:55 AM
I am in no way saying that an ATA drive will ever compare to a SCSI drive in speed. What I am saying is that it is cheaper to buy two huge ATA drives and use them in a array and end up with a setup that is not only cheaper then the 15,000Rpm SCSI but is also faster (read and writer through not access) and has lot more storage room.


I say SCSI is dead because in a sense it already is. The average consumer no longer uses SCSI in there computers it has been pushed into the high end market only. SCSI will end up if it isn't already just like Beta. Even though it is the better idea it just doesn't make in the main stream.

rjstanford
Oct 31, 2002, 01:49 PM
Originally posted by MacBandit
SCSI will end up if it isn't already just like Beta. Even though it is the better idea it just doesn't make in the main stream.

And unfortunately, other technologies are pushing down in the high end (large servers). Its been a while since we spec'd SCSI in anything other than an internal development server for example, and for those ATA would be fine if it was available (we're mainly an AIX shop). The reality is that SCSI now has an incredibly small "sweet spot" ... small enough to reduce future R&D efforts and keep prices high, which further reduces the sweet spot, etc, etc.

It was indeed a great technology, but one whose time has almost certainly passed.

death
Nov 3, 2002, 08:09 PM
Originally posted by MacBandit
I am in no way saying that an ATA drive will ever compare to a SCSI drive in speed. What I am saying is that it is cheaper to buy two huge ATA drives and use them in a array and end up with a setup that is not only cheaper then the 15,000Rpm SCSI but is also faster (read and writer through not access) and has lot more storage room.


I say SCSI is dead because in a sense it already is. The average consumer no longer uses SCSI in there computers it has been pushed into the high end market only. SCSI will end up if it isn't already just like Beta. Even though it is the better idea it just doesn't make in the main stream.

Just last week an associate, who runs a private server in his closet (who is certainly a mainstream consumer) had to replace his Quantum fireball after only 1 year of service. He ran it 24/7 in a hot server closet, and it started dying (sectors going bad, I think). He's now using SCSI. And btw, if you somehow think that servers only using SCSI is some great HD conspiracy created to justify $700 HD's that only hold 36GB, think again. IDE hard drives are built to fail after far less use, have worse latency/seek time penalties, have an inefficient bus...They lose on every category but cost and storage size. I have no idea what you base your strange ideas of IDE Raid beating out SCSI on, but it's not happening in the professional sector. I went to dell and looked at the PowerEdge servers...the only server I found that used IDE was a $1300 entry level. All the rest used SCSI. I have no idea why you think that SCSI is dying, please tell me.


The reason of course that I'm claiming that your harddrive isn't averaging 40 MB/s is that only one IDE HD gets that, and I'm betting you don't have it. I don't know how you benchmark it, (maybe you're looking at cached data? maybe you're just looking at the outer zone?)

Inhale420
Nov 4, 2002, 10:15 AM
Originally posted by Chaszmyr
I have a 20gb 15000 rpm SCSI drive from Seagate in my computer... let me tell you, its not that much faster. Unless youre using SCSI RAID you might as well go with IDE RAID over SCSI because its cheaper and faster.

i have an IDE RAID 0 setup on my pc, and it's definitely fast enough to notice a difference. apple needs to get a heads-up on some of these cool new technologies. except IDE RAID is like 2-3 years old now.

MacBandit
Nov 5, 2002, 01:18 AM
Originally posted by death


Just last week an associate, who runs a private server in his closet (who is certainly a mainstream consumer) had to replace his Quantum fireball after only 1 year of service. He ran it 24/7 in a hot server closet, and it started dying (sectors going bad, I think). He's now using SCSI. And btw, if you somehow think that servers only using SCSI is some great HD conspiracy created to justify $700 HD's that only hold 36GB, think again. IDE hard drives are built to fail after far less use, have worse latency/seek time penalties, have an inefficient bus...They lose on every category but cost and storage size. I have no idea what you base your strange ideas of IDE Raid beating out SCSI on, but it's not happening in the professional sector. I went to dell and looked at the PowerEdge servers...the only server I found that used IDE was a $1300 entry level. All the rest used SCSI. I have no idea why you think that SCSI is dying, please tell me.


The reason of course that I'm claiming that your harddrive isn't averaging 40 MB/s is that only one IDE HD gets that, and I'm betting you don't have it. I don't know how you benchmark it, (maybe you're looking at cached data? maybe you're just looking at the outer zone?)

I've never once said that an IDE raid setup could replace SCSI in a professional system. It would work just fine in a home semi/pro office though at lower cost and bigger size. If you read the whole thread you will see that I and others have explained my stance on SCSI death. Maybe death is too harsh a word how about it's fall out of mainstream. It has gone the way of Beta as I have said before. It is being used primarily for professional only use. That being servers and high end graphics/audio systems. That market is very small in comparison to the mainstream average computer user and that is what I base my argument on.

Chryx
Nov 5, 2002, 02:19 PM
Originally posted by Nipsy
Neither SCSI nor IDE are going to break 50mb/s (sustained) in single drive configurations anway.

Actually, my 120GB Western Digital special edition nudges up really close to 50MB/s sustained, the Seagate X15-36LP (15k rpm) is up around 65MB/s

(your point mostly stands, but your numbers were outdated :))

syco
Nov 5, 2002, 03:17 PM
Originally posted by Inhale420


i have an IDE RAID 0 setup on my pc, and it's definitely fast enough to notice a difference. apple needs to get a heads-up on some of these cool new technologies. except IDE RAID is like 2-3 years old now.
I think I heard on some rumor site that Apple is supposed to adapt RAID into their new PowerMacs.

death
Nov 5, 2002, 07:22 PM
Originally posted by Chryx


Actually, my 120GB Western Digital special edition nudges up really close to 50MB/s sustained, the Seagate X15-36LP (15k rpm) is up around 65MB/s

(your point mostly stands, but your numbers were outdated :))

Perhaps I should clarify. WD's 200 GB 8MB will benchmark at over 40 MB/s, but his 80 GB IBM will not. Your 120 GB model will read near the inner edge at slightly under 50MB/s, but it's outer edge will be under 30. Your basic inner/outer average will scrape 40, barely.

And as for MacBandit's statements about SCSI being Sorry but SCSI is all but dead with the price and speeds of the modern ATA drives, if you meant that few consumers buy it, I would agree with you. But it is not obscure like Beta (I assumed by this you meant that IDE's complete victory is inevitable) IDE will never replace it in the server/workstation market unless something truly remarkable happens, and there are many more important factors than raw transfer speed and cost. If you agree to this, then I am happy to agree with you, as I personally have never used SCSI in my house computers (not even in my server).

MacBandit
Nov 6, 2002, 12:12 AM
Originally posted by death


Perhaps I should clarify. WD's 200 GB 8MB will benchmark at over 40 MB/s, but his 80 GB IBM will not. Your 120 GB model will read near the inner edge at slightly under 50MB/s, but it's outer edge will be under 30. Your basic inner/outer average will scrape 40, barely.

And as for MacBandit's statements about SCSI being , if you meant that few consumers buy it, I would agree with you. But it is not obscure like Beta (I assumed by this you meant that IDE's complete victory is inevitable) IDE will never replace it in the server/workstation market unless something truly remarkable happens, and there are many more important factors than raw transfer speed and cost. If you agree to this, then I am happy to agree with you, as I personally have never used SCSI in my house computers (not even in my server).


I did not mean a complete victory by comparing it to Beta. There has not been a complete victory with VHS over Beta either. Beta is still a standard in most tv editing studios. It's just been relegated to pro and prosumer use only just as SCSI has. I personally have had several SCSI drives but not for several years now.

MacBandit
Nov 6, 2002, 12:14 AM
Originally posted by Inhale420


i have an IDE RAID 0 setup on my pc, and it's definitely fast enough to notice a difference. apple needs to get a heads-up on some of these cool new technologies. except IDE RAID is like 2-3 years old now.


I think maybe you inhaled too much at 4:20. All the new PowerMacs are capable of supporting IDE or SCSI raids internally in 2 drive ATA or 2 or 4 drive SCSI configurations.

beefstu01
Nov 8, 2002, 09:28 AM
C'mon. Who's holding out for solid state drives? (Segate had them a while back. No moving parts, no noise... it's perfect, except for the $5000 price tag for 5 gigs).

MacCoaster
Nov 10, 2002, 01:19 PM
Originally posted by MacBandit
I think maybe you inhaled too much at 4:20. All the new PowerMacs are capable of supporting IDE or SCSI raids internally in 2 drive ATA or 2 or 4 drive SCSI configurations.
Not by default, but as a BTO option.

Dr. Distortion
Nov 10, 2002, 02:29 PM
I'd never ever trust mission critical data to an IDE harddisk. Let's ask ourselves a question, try to answer honestly... If you were NASA and about to choose a harddisk which would be included in the next Mars explorer... would you choose IDE or SCSI?

-Dr. D.

shadowfax
Nov 10, 2002, 02:52 PM
Originally posted by Dr. Distortion
I'd never ever trust mission critical data to an IDE harddisk. Let's ask ourselves a question, try to answer honestly... If you were NASA and about to choose a harddisk which would be included in the next Mars explorer... would you choose IDE or SCSI?

-Dr. D.

i would definitely choose solid state.

ddtlm
Nov 10, 2002, 03:11 PM
This is the fastest drive available, the 3rd generation of 15,000-RPM disks from Seagate:

http://www.storagereview.com/articles/200209/20020901ST373453LW_1.html

They claim sustained transfer is 76-51 MB/sec, depending on the track. Not bad for one disk.

I've got a pair of Seagate's 10K.6 10,000-RPM 72GB disks and a pair of Maxtor's 10,000-RPM 36GB Atlas 10K-III disks... these drives are all quiet and they all run pretty cool. The Maxtor's are just barely warm in a Quicksilver case.

Won't deny that serial ATA is a good thing though.

daveg5
Nov 10, 2002, 03:44 PM
I am into pro audio and scsi has served me well and ide has served me well, they both have good and bad points. ant there are many sites that explain them for my audio work and all my os and multimedia programs are loaded on the very quiet and very cool and very fast seagate cheetah 15k.3 about $220 only 18gb but that,s much more than i eed as many of my 24-48 tracksongs are underone 1gig. the os now flies with the small access time and low cpu overhead. now for storage i use a wd with jumbo cache and a very quiet seagate silent drive about a $100 for 80GB. These work great for most of my average programs and what nots. after a song is completed I simply copy it to ide from scsi for storage and when it is ready to master i copy it back to scsi and save it on cdr for hard copy. I hate those new 1 year warranties on ide glad i got mine early. I will soon add another 15k.3 drive to take my u160 card to the limit using raid. a 128 tracks should be easy. I love scsi, i love ide why fight when we can be friends and both do are specific roles and compliment each other

syco
Nov 10, 2002, 03:56 PM
Kumbayah my lord...

daveg5
Nov 10, 2002, 04:38 PM
Originally posted by syco
Kumbayah my lord...
Kumbayah
Oh lord
Kumbayah
Great song!!!!
I plan on a new powermac next year and I am hoping for serial ata or at least ATA/133 4 ports. Apple is right now way behind at ATA/66 and ATA/100. but I would even love u160/320 on the motherboard.

daveg5
Nov 10, 2002, 04:45 PM
Originally posted by daveg5

Kumbayah
Oh lord
Kumbayah
Great song!!!!
I plan on a new powermac next year and I am hoping for serial ata or at least ATA/133 4 ports. Apple is right now way behind at ATA/66 and ATA/100. but I would even love u160/320 on the motherboard.

second have.
before anything though Apple needs to catch up and update its acient pci board to pci-x so we can really use those raids and other pci stressing cards, not to mention usb 2.0 for the scanners, and firewire2 4 ports each and 1 in front. i hate seeing more firewire ports on pcs than macs. back to 1MB L2 cache and real ddr capability, quieter fans, lower prices and if it is posible {does anyone know} tri and quad G4's for the mid and high line and of course give me one free.

BenderBot1138
Nov 11, 2002, 05:15 AM
I have a disk that is big and spins really fast too... it's called a frisbee ... but I wouldn't put any data on it.

daveg5
Nov 11, 2002, 02:00 PM
Originally posted by Nipsy
As a longtime SCSI holdout, the price performance ratio finally caused me to switch.

I have a 480GB RAID in my machine for $750, which gives me 90MB/s sustained read, and 75MB/s sustained write (4 x IBM 120GXP and a SIIG 133 RAID card).

For about the same price, I could have acheived these speeds with SCSI (2 Cheetahs and a Dual channel U160) card, and had a whopping 36GB to work with.

I still dislike some of the IDE penalties as far as read/write delays, but for anyone who's bothered, SCSI is always a BTO option.

Neither SCSI nor IDE are going to break 50mb/s (sustained) in single drive configurations anway.

It is impossible to justify the costs for consumers, business users, and anyone not dealing with db/video/48 track audio, etc.

IDE is about $1/GB, and SCSI is $10...people already complain that Macs are too expensive.

Notes:

SCSI Drives are always hot-swappable (provided they are in an appropriate carriage).

A dual IDE RAID on one channel will likely give 130-140% performance, because IDE does not process commands in parallel.

A dual SCSI RAID on one channel will usually give 160-170% performance, as SCSI accepts concurrent instructions.

New Seagate Cheetahs 15Ks do run quiet, and cool, but are still very expensive.

Memory round trips are measured in nanoseconds (~10), SCSI seeks start at 3MS, plus the round trip to the drive, so paging to a drive is still 30 times slower than visiting RAM.

daveg5
Nov 11, 2002, 02:38 PM
As a longtime SCSI holdout, the price performance ratio finally caused me to switch.

RE: I am still holding out proudly while accepting ide at the same time

I have a 480GB RAID in my machine for $750, which gives me 90MB/s sustained read, and 75MB/s sustained write (4 x IBM 120GXP and a SIIG 133 RAID card).

Re: price performance wise that is probably the best set up I heard the 8 MB buffer WD are slower then the 2MB buffer IBM's in Raid arrays, i guess the larger buffer gets in the way.

For about the same price, I could have acheived these speeds with SCSI (2 Cheetahs and a Dual channel U160) card, and had a whopping 36GB to work with.

re: my cost
Sonnet ATA/100 card $99
seagate fluid bearing 7200 ide $114
WD800JB 7200 ide $109
Seagate 15k.3 u320 15000 scsi drive $229
Atto dual 80 u60 card $30
{Seagate #2 15k.3 card not bought yet $229}
total: $810 140-150MB/s scsi raid
(2 x Seagate Cheetah 15k.3 and u160 card}
(1 wd800JB+1 segate fluid bearing 80GB ide drive and ata/100 card)
196GB unformated.
granted most people dont need 90+MB per second transfers or work with 48+ audio tracks and this is overkill but i am loving it. fast and lots of space. but i must admit your setup is probably the best for most non power users

I still dislike some of the IDE penalties as far as read/write delays, but for anyone who's bothered, SCSI is always a BTO option.

RE: and acces speed

Neither SCSI nor IDE are going to break 50mb/s (sustained) in single drive configurations anway.

RE: the 15k.3 does

It is impossible to justify the costs for consumers, business users, and anyone not dealing with db/video/48 track audio, etc.

RE: in most cases you are right

RE:

DaveG5:
I almost did exactly what you did, but for me I decided to keep both scsi and ide. I did not want to use ide raid because of an article in macworld that tested four of them and said each drive added only added 25 % to the transfer rate and cpu overhead.
also i can only fit 4 drives max and already had a u160 card and a loud first generation ibm scsi twice the physical size of drives now.
i wanted quiet, got a segate ide with fluid bearings Was twice as fast as my old 10000 IBM. i still cant hear it{would be great in a cube} then i heard of the wd 80GB jumbo model. i got that 25% faster then segate just a little noisier. now the choice: take scsi and ide cards out get 2 ide raidcards and 2 mor wd800JB's. thats what I was about to do until I saw the review of the 15k.3 on www.storagereview.com
. Since i plan on eventually doing more 64-128 tracks when i get a new powermac next year i knew that just one of these 18GB at $229 {5 year warranty} would almost equal your 4 drive array in speed{i will add 1 more later to saturate the 160MB limit of my card. and I still have 2 large ide drives for data storage. not a bad comprimise, not a comprimise at all

daveg5
Nov 11, 2002, 02:39 PM
Originally posted by Nipsy
As a longtime SCSI holdout, the price performance ratio finally caused me to switch.

I have a 480GB RAID in my machine for $750, which gives me 90MB/s sustained read, and 75MB/s sustained write (4 x IBM 120GXP and a SIIG 133 RAID card).

For about the same price, I could have acheived these speeds with SCSI (2 Cheetahs and a Dual channel U160) card, and had a whopping 36GB to work with.

I still dislike some of the IDE penalties as far as read/write delays, but for anyone who's bothered, SCSI is always a BTO option.

Neither SCSI nor IDE are going to break 50mb/s (sustained) in single drive configurations anway.

It is impossible to justify the costs for consumers, business users, and anyone not dealing with db/video/48 track audio, etc.

IDE is about $1/GB, and SCSI is $10...people already complain that Macs are too expensive.

Notes:

SCSI Drives are always hot-swappable (provided they are in an appropriate carriage).

A dual IDE RAID on one channel will likely give 130-140% performance, because IDE does not process commands in parallel.

A dual SCSI RAID on one channel will usually give 160-170% performance, as SCSI accepts concurrent instructions.

New Seagate Cheetahs 15Ks do run quiet, and cool, but are still very expensive.

Memory round trips are measured in nanoseconds (~10), SCSI seeks start at 3MS, plus the round trip to the drive, so paging to a drive is still 30 times slower than visiting RAM.