External enclosure eSATA speeds

Discussion in 'Mac Pro' started by lbeck, Nov 3, 2010.

  1. lbeck macrumors 6502

    lbeck

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    #1
  2. Transporteur macrumors 68030

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    #2
    That is right. You'd need a 6Gb/s eSATA (knows as SATA III) compatible enclosure. But still, the maximum throughput of 6Gb/s eSATA should be around 560MB/s.

    As mentioned before, by getting a 6Gb/s eSATA enclosure, or by choosing another (way more expensive) technology such as an SAS enclosure driven by a SAS controller card. Such a configuration can go even higher, with transfer speeds of up to 1GB/s.
     
  3. lbeck thread starter macrumors 6502

    lbeck

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    #3
    Thanks for response. So ...

    To get 600/Mbs I need an enclosure and card that supports it.

    Also, my mac pro will support those speeds as long as I buy the above hardware, right?

    I didn't know about SAS, tempting. What is a good brand for that? Any links?
     
  4. Gymnut macrumors 68000

    Gymnut

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    #4
    I just set up that very same configuration up in my home office last week with 4 WD 2TB Caviar Green drives and get around 150MB/s via eSata. I knew the green drives would be slower, but it's still faster than FW800 connection I had prior to installing the MaxPower eSata card. Very straightforward install, although I had to swap it from slot 2 to 3, after it initially OSX would not recognize it. Enclosure runs very cool and isn't loud at all.
     
  5. lbeck thread starter macrumors 6502

    lbeck

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    Is it only 150/Mbs because of the green drives? Does the MP support the 600/Mbs?
     
  6. Transporteur macrumors 68030

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    #6
    The Mac Pro supports speeds of whatever card you through in there (well it has to be compatible of course). A 16 lane PCIe slot (1 or 2) has a maximal throughput of 8GB/s, the upper two slots have 4 lanes each, so they are good for 2GB/s.

    Either way, the controller card, or even more likely the drives you connect to the controller, will limit your throughput, not the Mac Pro.

    Just FYI, the correct notation is 150MB/s. It's Megabyte per second, not to be confused with Megabit (Mb, or Mbit).
     
  7. philipma1957, Nov 3, 2010
    Last edited by a moderator: Nov 11, 2010

    philipma1957 macrumors 603

    philipma1957

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    #7
    I USE the owc qx2 with 4 wd caviar black in a raid0 I get about 190mb/s I had used it with 4 samsung f3 1tb hdd's and it pushed 210mb/s. why do you want 400 to 600 mb/s? It will cost you money. it won't be a booting enclosure. the mac pro will use a pci e card and an enclosure and you really shold use good high end hdds like wd re4 2003fyys 2tb raid hdds at about 250 a pop.

    Now I use sans digital and they have been good for me but I have no experience with this gear
     
  8. Gymnut macrumors 68000

    Gymnut

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    I suspect it is the green drives; I knew I'd be taking a performance hit using them, but they were $109 each and I've got them set up in a RAID5(The OWC Elite-Al Pro Qx2 is by default set as a RAID5 out of the box). As Transporteur pointed out, the card supports 6GB/s eSata, you need an enclosure that supports it as well. I don't know any enclosure off the top of my head, and I don't think OWC sells any of yet.

    I'm sure if you were to fill it with faster drives(Caviar Blacks, RE3, etc.) you'd get faster throughput.
     
  9. lbeck, Nov 3, 2010
    Last edited: Nov 3, 2010

    lbeck thread starter macrumors 6502

    lbeck

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    #9
    Thanks man :)

    I'm surprised you only get 190MB/s with the caviar blacks. How the heck do you get close to the advertised 300MB/s?

    The reason why I want the top speeds is because I'm a gear head and paid a lot of money for my equipment so I want to get the best possible output. Especially if I buy an eSATA card and enclosure, I want to get the top speed, or close to it.

    I didn't realize that the speed could vary so much. How do you get top speeds of 300 or 600MB/s? Does it have something to do with a multiplier? Not sure what that is.

    Also, if you have 4 HD's in an enclosure and only one eSATA cable going into the MacPro, all four drives have to split up the speed. Right? Or am I crazy for thinking that?
     
  10. philipma1957 macrumors 603

    philipma1957

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    #10
    300MB/s will never give sustained rate 220 to 250 it will do. 600mb/s will never give sustained rate of 600

    480 to 540. okay say you buy the qx2. the fastest is 4 drives in raid0 there are other setup raid5 or raid10 with the qx2 from owc raid0 will give you a solid 190 to 200 with the blacks but it is risky and if it fails all is lost plus no booting. I believe only one card boots a rocket raid type from high point and it is a card that fails a lot. raid10 is slower maybe 160 sustained speed but it doe not fail easy and has a backup. the downside is raid10 turns 4 2tb drives into 1 4tb volume with a copy. so it is smaller and slower but since it has a copy it is safer then raid0. raid5 does not run well on the qx2 nanofrog is the member that could explain it best. so with a qx2 you can use 4 2tb drives as a fast big 8tb raid0 or you could use 2 2tb drives as a little slower smaller 4tb raid10. it will not boot with the card you picked out. if you go out and get the bigger sans digital you can run more raid setups raid6 raid5 raid0 raid1 raid10. plus the sas cable is better it allows a longer cable and a better connection. it will cost 679 for the case and i think you will need a better card then the one in the box so maybe 900 to 1 k with 0 drives then the drives. I went with the less costly and used a raid0 in the pro itself I am getting 400 read 400write with 4 caviar blacks and i use the outside drives to make backup copies of the mac pro raid0. and my raid0 in the pro boots. I keep it at about 850gb out of 6tb.

    it was the cheapest way to be fast but this machine is not for work it is for my personal use.
     
  11. lbeck thread starter macrumors 6502

    lbeck

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    #11
    Why doesn't the enclosure from OWC work well with raid 5? It's advertised as doing so. I'd probably do raid 1, 5 or 10. Definitely not 0 for security.

    Does the card have to support booting for me to be able to boot from my enclosure? I'd never boot from my external enclosure unless my internal boot drive failed. But I'd need that option if that happened.

    If the card i posted in the original post does not allow me to boot from the enclosure then which one from OWC will do that?
     
  12. nanofrog macrumors G4

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    #12
    If you're after RAID 5, you'll be looking at a proper RAID card, not eSATA card (OWC's enclosure has it's own hardware chip inside the box). BTW, this isn't the cheapest route to go, as the hardware is more complicated (but you do get something for your money, so it's by no means a waste). It all depends on what your actual needs are.

    Now you can use software implementations of 0/1/10 (little overhead), but to use 10, your usable capacity is only half the total capacity of the disks in the set (i.e. 4x 2TB disks will only give you 4TB of usable space).

    There's options, so settle on a RAID level if you're heart is set on it. Then we can go from there. ;)
     
  13. philipma1957, Nov 3, 2010
    Last edited by a moderator: Nov 11, 2010

    philipma1957 macrumors 603

    philipma1957

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    #13
    the owc case can be used for a nice backup in raid10 which means 4tb max. if you have to use it to boot you pull the esata cable out and plug the fw800 cable in and boot-a-ruler it boots. this is how i use it. I run my internal 4 hdds in a software raid0 and I make 4 backups and TM of the internal volume. but I don't use this for business like a lot of user here do. oh i resell some hdds and parts I build some small raid0 setups. i don't do large graphic work. Now if my internal setup dies on me In a day it gets fully restored and i can use other machines to make some IT setups.

    Now I like having a fully equipped piece of gear. My base model has 4 sticks of 4gb ram it has 4 1.5tb caviar black hdds. it has the better graphics card.
     
  14. lbeck thread starter macrumors 6502

    lbeck

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    Currently I use RAID 1 so I only get half capacity of my enclosure anyway. I'd like to keep it that way but will now use RAID 10 to get the benefit of speed.

    So if I use RAID 10 is the OWC enclosure a good way to go? the only thing I don't like about it is it only has 300MB/s.

    And does only having one eSATA plug affect the overall speed?
     
  15. nanofrog macrumors G4

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    #15
    This is fine, so long as you can deal with the cost of the drives, enclosures,... (in general, as those costs tend to matter for large scale storage systems).

    It would certainly work, but you don't need that enclosure to do level 10. Disk Utility is fine doing that, so you could get a Port Multiplier enclosure instead (potential to fit more disks, depending on the actual enclosure used). PM enclosures usually come in 4, 5, 8, and 10 bay versions (sufficient drive bays for a level 10 array).

    Instead, you could go with the newertech RAID eSATA card (has PM support; the cheaper one does not) and a Sans Digital TR8MP (8 bay PM enclosure kit, but the card won't work with OS X; the enclosure only version is the TR8M, but may be harder to find; newegg's discontinued it).

    Yes. You're pushing the output of multiple disks over one port, so it's definitely a bottleneck. But it may be acceptable for some, especially in situations where the budget is really tight (always a compromise.... :rolleyes: ;)).

    BTW, PM chips will reduce the throughputs a bit too (i.e. 3.0Gb/s compliant PM chips tend to hit ~250MB/s max no matter how many drives are on it).
     
  16. lbeck, Nov 4, 2010
    Last edited: Nov 4, 2010

    lbeck thread starter macrumors 6502

    lbeck

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    #16
    Thanks Nanofrog, I appreciate your help.

    1. Both the TR8MP, and the TR8M at OWC only support 1.5TB drives. Do you know of a PM enclosure that holds 8, 2TB drives for a total of 16TB? That way I could eventually use RAID 10 for all 8TB in my MacPro.

    2. I'm trying to figure out how I would use multiple ports so the speed increases. I know the Newer Tech Max Power Card supports PM, but how does one go about using PM? Is it just a case of using more than one eSATA cable? For example, if I were to get the TR8M at OWC and Newer Tech Max Power Card how exactly do I ensure that PM is working so that the speed is increased?

    3. And if I get the Newer Tech Max Power Card that supports PM and 6Gb/s, my hard drives as well as my enclosure have to be 6Gb/s as well to get that speed, correct? I was planning on getting the Caviar Black drives and they are only 3Gb/s. Any recommendations for 2TB 6Gb/s drives and a 6Gb/s enclosure? Or are there not any good, reliable drives like that right now. Only one I could find is the Seagate
     
  17. philipma1957, Nov 4, 2010
    Last edited by a moderator: Nov 11, 2010

    philipma1957 macrumors 603

    philipma1957

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    #17
    this unit will hold 8 2tb drives.

    http://www.newegg.com/Product/Product.aspx?Item=N82E16816132016&Tpk=rosewill rsv-s8

    i own one and it is going on sale at 1pm east coast to 4pm east coast time it will go for 219.99 i run it with 8 hdds each one as jbod

    this rosewill is a clone or rebranded sans digital. it has 2 esata jacks . it is low cost way for a lot of storage read the reviews mine is there under philipma1957
     
  18. nanofrog macrumors G4

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    #18
    The Sans Digital enclosures can handle 2TB disks (what you saw was probably typed in before 2TB disks came out to represent the current max capacity for that time).

    It's a good idea to check the manufacturer's website for updated information (it may not always be there, but in the case of Sans Digital, it is; TR8MP specs). ;)

    Use the newertech PM compliant card, as the included card with the enclosure won't work under OS X, as it's a Highpoint RR722, and they've not developed drivers for it (TR8MP = kit; it seems they no longer sell the enclosure without a card).

    BTW, if you can live with black, then philipma1957's link is a cheaper option (Rosewill = newegg brand, and is exactly what he said it is; a re-branded Sans Digital unit).

    As per the connections, Yes, you attach one cable per port on the enclosure and card (both ports will be used on the enclosure and card).

    Now to performance.
    There's 2x eSATA ports on the back of the unit; one port per 4x disks (this is what the PM chip does; switches one eSATA port to multiple disks, in this case, 4 of them). So drive bays 1 - 4 is on one port, 5 - 8 the other.

    So you need to figure out what the best drive locations are to utilize the additional bandwidth. For example, if you're running a 4x disk stripe set, you'd better off running 2x disks in the first grouping (bays 1 - 4), and the remaining 2x disks in the second group (bays 5 - 8). This would double your bandwidth, as the signals are carried over both eSATA ports, and is balanced (you want to keep the bandwidth as similar as possible, which means the same disk count per port if at all possible).

    The RAID would have to be created under Disk Utility, but you'll see the disks. Once created, an array will be seen as a single logical volume (i.e. n member array will be seen as one drive by the system).

    See above. The 3.0Gb/s Caviar Black drives will be fine (there's not a single mechanical drive that can generate enough throughput to saturate a 3.0Gb/s port, including the linked Seagate drive). What we'll see, are 6.0Gb/s compliant chips used in mechanical disks (can help with compatibility when connected to a 6.0Gb/s SATA port in the system or on a card; seen it before during the 1.5 to 3.0Gb/s transition).

    Nice price (I don't usually check on this one, as it seems most would prefer the silver Sans Digital units to match their MP's aesthetically). I haven't seen a decent 8 bay PM enclosure this cheap in a while (used to find them for ~$250, but now have hit or exceeded $300).
     
  19. philipma1957 macrumors 603

    philipma1957

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    #19

    It is even a bit better I picked one up today for the 219.99 and I added the free combo for a spare tray. Grand total is 219.99. sale is good until 4 pm east coast time. this second unit will be used with the pro . I am going to sell off the owc qx2 unit.
     
  20. nanofrog macrumors G4

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    Sweet deal. :D

    The Qx2 should find a buyer on eBay (though inexpensive and lightweight in terms of throughput, hardware RAID 5 is a good selling point IMO). ;)
     
  21. philipma1957 macrumors 603

    philipma1957

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    #21
    yeah i can sell it pretty quickly. these 8 bay units are much better for my needs. Plus a free storage tray is cool. I have all those small ssds I can drop into it.
     
  22. lbeck, Nov 4, 2010
    Last edited: Nov 4, 2010

    lbeck thread starter macrumors 6502

    lbeck

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    #22
    Awesome, thanks Nanofrog and Philipma! Lots of good info. So ...

    I like the aluminum Sans Digital, apple has burned in my brain that I must have great looking hardware. It's gotta match :). Wish I didn't feel that way cause the $219 is a great deal.

    I'm going with the aluminum sans digital since it can fit 2TB drives for a total of 16TB. OWC sells it without the card (link in my other post) but it's the same price as the one with card. Just to be sure, the one from OWC is the proper enclosure that can hold 16TB, right? I'll also buy the card from OWC that supports PM.

    Is overall speed slower with a software RAID? If so, doesnt the card I'm buying from OWC provide a hardware RAID?
     
  23. nanofrog macrumors G4

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    #23
    You're not the only one, which is why I linked the silver versions of the Sans Digital enclosures.

    They also work well, have good prices (really good price/performance ratio), and offer additional value in the fact the external cables necessary are included (not that big a deal with the eSATA versions, but it is with the SAS variants, as those cables are ~$60USD each <1.0 meter>).

    Yes.

    Both the TR8M and TR8MP are the same enclosure, and will support 2TB disks (the TR8MP is just the kit; same enclosure and it includes a Highpoint RocketRAID 722).

    So either one will work. You could sell off the RR722, or use it for Windows/Linux (same or different machine). Up to you, as both newegg and OWC are good companies to deal with.

    Yes, and it's due to several factors.

    The actual variance will depend on the specifics however, so don't panic (mainly the number of drives used). For example, the throughputs of say a 2x disk stripe set will be similar between the ICH, eSATA card, and proper RAID card, given there's one port per disk. But as you scale up te member count, things change (and fast for PM based enclosures, as you're sharing one port with multiple drives).

    True RAID cards can be used with one port per disk, and can have a substantial number of ports (up to 24). So there's additional bandwidth for parallel disks which results in much higher throughputs. The processor and cache on the card can also speed things up as well, but the additional bandwidth is the real key as to why they can blow the doors off of the ICH and a SATA/eSATA implementation. But you pay for it (and it can be quite handsomely in fact, as it doesn't take much effort to hit $3k USD for a fairly modest DAS).

    Now assuming you've one port per disk, the independent processor and cache can further push throughputs for an array vs. the ICH or eSATA + PM implementation you're planning (again, keeping this to one port per disk; once you're running multiple disks on one port, the comparison isn't really valid, as it's an Apples to Oranges situation).

    But unless you're doing 3D graphics work, scientific simulations,... (stuff that requires some serious throughputs), you don't need a proper RAID system. So I suspect the eSATA + PM method will do you just fine (more than fine if you've a large movie and/or music library you're trying to store). ;)

    No. It's nothing more than a SATA controller chip and software, which is why it's so cheap.

    If you were looking at a true RAID card, starting prices (4 port models), usually start ~$300USD (bit less on occasion, but not much). And they can go over $1k USD (24 port units). :eek:
     
  24. dknightd, Nov 5, 2010
    Last edited: Nov 5, 2010

    dknightd macrumors 6502

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    #24
    The TR8MP comes with the highpoint RR622 card

    http://www.newegg.com/Product/Product.aspx?Item=N82E16816111140

    That card works fine in a mac pro. I use it for JBOD, haven't tried its (software) raid capabilities.

    As near as I can tell, the newertech card
    http://eshop.macsales.com/item/Newer Technology/MXPCIE6GRS/
    looks alot like the RR622
    http://www.sansdigital.com/esata-port-multiplier/ha-hig-rr622.html

    (might be the same card with different board color and graphics???)
    The software looks very similar too . . .

    Edit: btw, neither card will give you true esata 3 speeds because both only use one pci channel
     
  25. philipma1957 macrumors 603

    philipma1957

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    #25
    I use the rosewill clone with jbod i use the newertech card. My drives caviar black are about 145MB/s and fade to 115MB/s if you go deep into the drive. What is nice I have 1 drive with all eyetv recordings. I have a clone of it also.

    I have a few drives setup up as backups of the raid0 that is in the macpro. the raid0 in the macpro flies read and write are at 400MB/s . I keep it light about 1tb out of 6tb I can let it grow to 1.8tb/ i use a 28 dollar version of superduper to make a mon wed fri clone of the raid0 0 in the pro. so that is 3 drives. I have a few other drives with music and movies. It works and is lower cost. it is a good setup for hobbyists that don't do long video edits. would be good for a gamer etc.
     

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