Serial ATA Raid Card for the UK

[haravikk]

Okay, I've been popping in and out of these forums for a while, but only actually signed up today to make a few replies to threads here that are looking at similar things to me.

Basically what I'm trying to do with my PowerMac G5 (Dual 2.5ghz) is remove as many of the bottlenecks as I can. The first step for this was to get some more RAM, you might not want to think it but 1gb does actually limit such a fast machine, 2gb ought to help a lot there.
However, the problem that is still left is that of actually getting information into this 2gb of RAM in the first place, namely from a hard-drive. The only internal drive I have is the 160gb SATA drive my G5 came with (7200rpm, around 60mb/sec transfer rate). Although this is fast, it is still a limiting factor in the G5.
At first I looked at simply getting a faster single hard-drive, so I looked at the Western Digital Raptor, which is a formidable drive with 74gb space and a 10,000rpm speed, but for all it boasts it sounds like it isn't as big a step-up as I would like, add to that the cost of £120 (or £75 for the 36gb version) and it really doesn't pack all that much power-per-pound.

So what I'm now looking at is instead getting two much cheaper (and still very speedy) 80gb drives, the ones that I have found are actually surprisingly inexpensive at £38 a piece:
http://www.pixmania.co.uk/uk/uk/36288/art/seagate/hard-drive-barracuda-7200.html

So that's the two hard-drives out of the way. What next? Well, my G5 only has one spare drive spot, and I don't want to replace my 160gb drive, so what I now need is a good SATA Raid controller PCI card which will allow me to attach two or more internal hard-drives.
And now I'm stuck. I keep finding such cards that offer Mac compatibility, but I then can't find any for the UK, with the expection of one over-priced card at £65 for only two connections (a similar card by a different manufacter would cost around $55).

So I've found my way back here to ask if anyone knows of a good card for the UK, I'm looking around £40 (£50 tops) I think to keep my RAID assembly around the £125 mark (plus any extra cables I need).

While I'm at it I think I'll also ask, since I'm installing two internal drives (both on the card I think, leaving my spare built-in bay free for a bigger drive later) then I'd also like to know what cables I'll need, most importantly power and where I connect these. I'm under the impression that it goes in the back of the SuperDrive, but I'm not certain what I need for this.

 

[R.Youden]

Welcome.

I am after a similar PCI card. I currently have a G4 powermac which dies not come with an SATA connector so I have to get a card so I can add a 74GB Raptor. Would it not be possible for you to get a normal card and use RAID software to set it up. I know people say they rather set it up via hardware but by all accounts the software setup is not too bad. I to am based in the UK. If you go find one of there cards post back.

Richard

 

[haravikk]

Sorry I should have said that the Raid part isn't overly important, but I'm finding it hard to even find one without built-in RAID functionality

 

[R.Youden]

The thing I want to know is what makes a PCI mac compatible? why is a £20 SATA card not Mac compatible? I imagine it is something to do with install software. Try looking on kelkoo or Deal Time I am sure you can find something on there. Let me know how you get on.

 

[Blue Velvet]

Apart from a Sonnet Tempo card (about £65), I can't see much around in the UK.

Where are you going to put these internal drives anyway? There's not much room in the G5. Two HD bays at the top back, one optical bay at the top front...

Worrying about these 'bottlenecks' comes to a point of diminishing returns. We have the 74gb Raptors in our work G5s, they've made a big difference but (allegedly) Tiger will offer you increased zip in the Finder at least. Get one of these and be done with it, throw any extra money at RAM IMHO.

G5 internals:

 

[drlunanerd]

You've not made it clear what you're trying to achieve here as far as I can tell. I think you mean you want to set up a striped RAID array with two 80GB disks? But then you say RAID isn't important to you You also don't mention the problem (and expense to solve) of fitting two internal disks in the PM G5 case without using the spare slot you currently have. It's possible but you'll need to buy an adaptor kit from the likes of WiebeTech, but they're probably not going to be cheap which rules them out for you.

IMO it's just not worth the hassle for you. You'll not get much of a performance benefit - after all youu've already discounted the 10K drives on that basis. You'd probably be better getting a higher density SATA drive (like a 400GB 7200rpm) wich should provide a performance boost over your stock drive. Try checking out www.barefeats.com for SATA controller and hard disk performance tests.

I looked into SATA cards myself not long ago and couldn't find any Mac versions for less than the prices you're quoting. www.macsales.com do the FirmTek ones, but of course they ship from the US but that isn't necessarily a problem if you like paying VAT and import duty! I believe you cannot use PC cards due to firmware differences.

 

[CanadaRAM]

The BIOS on the SATA card has to be Mac compatible. Sonnet and FirmTek make SATA and RAID cards.

You're not going to install 2 more drives internal to your G5 - there isn't space to put them. You will have to go with an external SATA enclosure.

RAID is iffy as to whether it is faster than a single drive for typical single-user desktop use. The overhead of RAID probably nullifies the speed improvement for normal use.

Use RAID only for servers under multi-user loads and for video/audio production where you have sustained streaming of very large files.

Go with BV's suggestion - install a Raptor for your System and Scratch drive and be happy.

BTW: Look out for a gotcha on those half-price Seagates, they might be reconditioned or "recertified" drives, they might have 1 year warranty instead of Seagate's 5 year. or if they are pulls from PCs, they might be OEM drives with no warranty from Seagate at all.

 

[drlunanerd]

You're not going to install 2 more drives internal to your G5 - there isn't space to put them. You will have to go with an external SATA enclosure.

Yes, you can. Sorry to be devil's advocate here, but check this out: www.wiebetech.com/products/G5Jamplus.php

It uses the space at the back of the PCI slots, but of course prevents you using long PCI cards.

Agree though it's not worth the hassle for a desktop, but a lifesaver for servers - RAID 5 has saved my bacon loads of times

 

[CanadaRAM]

Yes, you can. Sorry to be devil's advocate here, but check this out: www.wiebetech.com/products/G5Jamplus.php

It uses the space at the back of the PCI slots, but of course prevents you using long PCI cards.

Agree though it's not worth the hassle for a desktop, but a lifesaver for servers - RAID 5 has saved my bacon loads of times

Given that the cost of the Wiebetech case mod is more than the cost of external SATA enclosures, and that the original poster was concerned about saving 20 quid on the drives, I would guess that this is a non-starter.

BUT Please please don't confuse the issue by equating RAID 0 with RAID 5.

A 2 Drive RAID has to be RAID 0 (Striping for speed) or RAID 1 (Mirroring - provides redundancy at the cost of 1/2 the drive space and slower access).

As the OP was concerned with speed, they are talking about RAID 0, where data is separated between two drives for faster access, and there is no redundancy or data backup provided. The problem is, that if you have a failure on any one of the drives, all data on the RAID 0 volume is liable to be lost.

A RAID 5 array is a group of 3 or more drives, which combines striping (speedup) with a "checksum" drive for data security. You can lose any one drive out of a RAID5 array and still recover all the data by rebuilding the lost data from the checksum data.

But a RAID 0 doesn't have this, and is many times more risky for losing data than a single drive.

 

[haravikk]

Thanks for the replies guys! After searching about exhaustively I think it's becoming clear that SATA cards for Mac aren't in a very good state for users looking to create small arrays like I am.

What I think I'm going to do instead then is simply buy a second identical drive to the one the G5 came with (Seagate Barracuda model ST3160023AS - 160gb), and when I come to install Tiger I will move my stuff to my external drive and then set-up the (then) two 160gb drives into a RAID-0 configuration. This way the total cost is only £65 after a bit of searching for the right model of Barracuda drive. Once I've striped the drives I will then partition them (if that's possible with RAID arrays?) and put Tiger into it's own partition and everything else in the 'main' one.

The plan is to use my external 80gb drive as a back-up drive for the most important folders, synching them periodically or using spare processor time depending on the software I can find/afford to use for that purpose.

I think that this ought to have the higher overall performance gain for minimum cost, as a RAID-0 configuration should give twice as much speed, I realise that this bonus goes down as the drives fill up, but I don't expect to use 320gb any time soon anyway so it ought to be fast.

The reason that I'm not want to go for the Raptor is that it costs twice as much for half the capacity I could get, and it's very uncertain what kind of speed benefit it gives in comparison to a RAID set-up.

Also, in response to the comments about where to put the extra hard-drives, there is enough space in front of the front fan-block for 3 whole drives, there is further space for another drive above the Optical Drive bay, this brings a G5 to a total of 6 drives if you want them. If you have empty PCI slots, or only have 'short' (ie not full-length 16cm) PCI cards, then you can also fit another two or three hard-drives in there if you buy a replacement air-baffle (the clear plastic screen under the side panel) or can build an alternate solution, bringing you up to eight or nine. Take each of those at 400gb and you've got yourself 3.2 or 3.6 terabytes in that G5

 

[Blue Velvet]

Also, in response to the comments about where to put the extra hard-drives, there is enough space in front of the front fan-block for 3 whole drives, there is further space for another drive above the Optical Drive bay, this brings a G5 to a total of 6 drives if you want them.

You don't think there are cooling issues related to cramming drives in left, right and centre? For all the hassle, an external solution would be better.

 

[drlunanerd]

I wouldn't recommend going down the software RAID 0 route. You will not get twice the performance and you'll be introducing more potential failure points into your system (like CanadaRAm says, one drive goes down and you lose the whole array). I advise genning yourself up on RAID and all its intricacies, and/or check www.barefeats.com out for real-world performance tests. After all, what is that point of all this if you won't significantly improve the so-called bottleneck that is your current stock drive? I get the impression you don't want to be wasting money to find this out.

As BV says cramming drives in there will add stress to the cooling system and again introduce more potential failure points. I only mentioned the WiebeTech solution to correct CanadaRAM's assertion that it cannot be done, but stated previously that it would likely be out of your budget.

 

[haravikk]

Well yeah I don't intend to shove 9 drives in there, but most hard disks generate very little heat, and as long as you're careful about the spacing then the G5's internal fans should be able to cope with it except under extreme use (ie if your processors are working full-out for an extended period of time).

Thanks also for that barefeats article, thought it does actually show the kind of results I'm looking for, as it looks like the speed benefit I will achieve is roughly equal to (if not higher than) the speed of a single raptor, but at half the cost and a considerably higher capacity by around 4 times.
The article doesn't however appear to make any notes on general system performance under each configuration, nor does it measure things like loading times once within UT2k4.
The two results I'm most interested in are the big file-movement values and the small read/writes as that's where the bonus of the 'doubled' bandwidth comes in for things like file-heavy web-serving or image manipulation.

As I've said the risk of a failure isn't a massive concern as things I do not want to lose will be backed up to an external drive.

I think the best set-up would really be a RAID with more than two drives, but that's a bit out of my price range as the cards alone are over £100, even an ATA 133 RAID set-up with a load of small drives would be costly. I think the 160gb identical drive is what I'm going for, I'll set it all up as a Raid-0 and run some of my own benchmarks and tests in comparison to where I am now, see what I come up with, if it's not much better then I'll stick with two seperate disks, one with the OS and one with everything else (well the OS disk would be used for general files too if the second fills up).

 

[CanadaRAM]

Thanks for the replies guys! After searching about exhaustively I think it's becoming clear that SATA cards for Mac aren't in a very good state for users looking to create small arrays like I am.

Why would you say that? Sonnet and FirmTek have excellent SATA cards. IF you are willing to get technical with compatibility, SIIG and ACard cards apparently will also work, but who wants the hassle?

What I think I'm going to do instead then is simply buy a second identical drive to the one the G5 came with (Seagate Barracuda model ST3160023AS - 160gb), and when I come to install Tiger I will move my stuff to my external drive and then set-up the (then) two 160gb drives into a RAID-0 configuration.

I think that this ought to have the higher overall performance gain for minimum cost, as a RAID-0 configuration should give twice as much speed...

Baaad idea. First, the speed gains of RAID (as posted by Barefeats) are on high volume, sustained transfers. Exactly what you do not do with a boot drive in a desktop configuration. You have an excellent chance of decreasing your perfomrnce with this configuration. Plus your risk of catastrophic failure is increased greatly with a RAID 0 boot drive.

If you want some unbiased information on RAID, see StorageReview.com
http://faq.storagereview.com/SingleDriveVsRaid0
http://www.storagereview.com/articles/200406/20040625TCQ_5.html

"RAID 0 does have its advantages in a handful of key applications and uses where data files are huge and/or data requests are highly sequential in nature. Data requests are not highly sequential, however, in typical desktop productivity and most gaming usage patterns.

The point? Dont assume RAID 0 offers increased performance for all or even most applications... and dont assume that transfer rates reflect application-level performance.... the increase in transfer rates and high-I/O random access performance delivered by RAID0 simply do not benefit most non-server uses."

The reason that I'm not want to go for the Raptor is that it costs twice as much for half the capacity I could get, and it's very uncertain what kind of speed benefit it gives in comparison to a RAID set-up.

The point of the Raptor is not data storage, it is fast access to the small files in the System and scratch disk. The performance benefit has been attested to by BlueVelvet in their production environment.

Also, in response to the comments about where to put the extra hard-drives, there is enough space in front of the front fan-block for 3 whole drives, there is further space for another drive above the Optical Drive bay, this brings a G5 to a total of 6 drives if you want them. If you have empty PCI slots, or only have 'short' (ie not full-length 16cm) PCI cards, then you can also fit another two or three hard-drives in there if you buy a replacement air-baffle (the clear plastic screen under the side panel) or can build an alternate solution, bringing you up to eight or nine. Take each of those at 400gb and you've got yourself 3.2 or 3.6 terabytes in that G5

Ooooh boy.

A few words to the wise

Heat
Warranty
Power - you're going to be really unhappy when your G5 power supply blows out
Cost - the internal bracket thing costs more than an external SATA case.

Do yourself a favor: Don't RAID your boot volume, and choose external SATA enclosures if you must set up a RAID. http://www.firmtek.com/seritek/seritek-1en2/


Edit: Darn servers...