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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Typical RAID speeds?

Christopher Barrett

Christopher Barrett

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I have some questions that stem from a digression of the new Mac Pro thread: What sort of speeds are you getting out of your RAID boxes and what is your configuration?

I use an 8 bay iStorage Pro SAS Expander box with 2TB drives connected to my 12 Core MP via the ATTO R680. When new, I was getting about 850 MB/s read/writes (which matched the dealers stats). I decided to go RAID 6 to keep a ready replacement drive on hand and my RAID is over half full so my tests are accessing the slower part of the spindles. I'm not surprised my performance is down given all this. The new Promise TB2 8 bay tests out at 850 MB/s / 750 MB/s over at FCP.co (though for some reason Promise uses 5900RPM drives in the 8 bay).

I'm just curious, what sort of speeds are people getting out of their boxes and what are your configurations? Transfer Rate / # of Drives / Interface???

Cheers,
CB
 
I get a bit over 700MB/s on my 6x3TB in RAID-5 on the Pegasus R6 Thunderbolt RAIDs. I just took delivery of a new Pegasus2 withe the same 18TB configuration and it runs about the same speed.

4 x 2TB WD RE4 drives in a RAID-0 inside a Mac Pro tower should deliver a sustained 395MB/s read and about 360MB/s write speed. The latest and greatest 3TB HDD's will give a small boost over that.

My 24TB RAID in a SansDigital SAS enclosure, connected to both external SAS ports on an ATTO R680 is an 8x3TB unit in RAID-5. It gives almost 900MB/s read and 800MB/s write - pretty much the same as the 8-drive Pegasus2. I could also get almost the same speed results connecting two G-SPEED Q enclosure units with 2TB HDDs to the ATTO host in RAID-5.

A lot of the speed considerations here are determined by the hardware and drive capabilities. For Christopher's configuration, his seems a bit on the slow side for the number of drives and the RAID host is a good one. Although, I'm not sure which iStorage Pro SAS expander he's using. If it's connecting via a single 4-channel SAS cable, then the speeds are right where they should be, so that's my guess. If it connects via dual SAS cables, then perhaps the drives used are affecting speeds. Some drives slow down a bunch as they fill up, others don't. Depends on which drives and how they arrange their data.

Generally speaking, hard drives will give you 120 to 150 MB/s read speeds. So if you have 8 of them striped together you're getting nearly 8X that read/ write performance. When you factor in other things such as RAID redundancy and parity as well as some overhead, the overall speeds drop. So you're not going to get 1GB/s out of 6 drives in a RAID-5 configuration. You can almost do it with 8 drives in a good configuration. It seems the 8-drive Pegasus2 could go 1100MB/s or faster in RAID-0, but that's not really how we would want to use it.
 
I get 600-650MB/s out of my Pegasus R4 with 3TB or 4TB drives. I get the same out of my Sonnet RAID (R800) with 8 3TB or 4TB drives and an ATTO R380. With an R680 I get 700-800MB/s. The RAID is a pair of SAS connectors.

Anyone have any drive speeds to share with 2.5" stock? I'm building an 8 slot thunderbolt chassis out of a sonnet box for rack mounting and need to go 2.5" drives. Curious if I'd gain anything with 12 drives over thunderbolt vs 8 and if I'll see 650+MB/s if I host them with a R680 or similar card (for 8 Drives) and a H6F0 (for 12 Drives).
 
2.5" drives are going to be slower and obviously lower capacity. The H6F0 host is just a SAS host with no frills and no RAID controller, so you will be limiting yourself to software-based RAID in that situation. Although, since it's a multi-slot PCIe expander with drive bays, you really just need an all internal RAID host. So in terms of ATTO that means R608 or R60F, 8 and 12 SAS/SATA channels respectively. You should also take a look at the ARECA RAID controllers.

While the 2.5" drives are relatively slower, I think a RAID made of 12 x 1TB 7200rpm drives would still be very snappy and should still give you 750+MB/s performance in RAID-5/6. If you're adding more PCI cards into the mix, that's going to cut down on bandwidth. Attaching to a new Mac Pro, each TB2 header only has a real-world max throughput of about 16.5Gbps, as they sit atop a PCIe v2.0 X4 interface and that bandwidth is for both ports on the same header.
 
I have an Atto R608 running at x8 speed, with non-enterprise 8 Hitachi 7K400 4TB 7200RPM drives (taken from the external USB3 versions I found a killer deal on a few months ago), and I'm getting 1,100 MB/s read and write. The drives are stacked internally in my tower case (a SilverStone Temjin TJ04E). Initially I was getting slower speeds, and then at one point 900MB/s read and 1,200 write, but preferred the 1,100 MB/s speeds so they were more equal. This is was done by experimenting with the settings when building the array, such as sector size, speed read, etc., and not using the DVRAID feature.
 
The 7K400's are speedy drives. I haven't worked with them much and have had a couple fail in the little bit of time I've played with them, so no RAID usage here. Hitachi has not released enterprise/ RAID editions of those drives just yet. Most of the other 4TB drives on the market are currently lacking in the performance department.
 
New system here has an LSI 9361-8i and 8 Seagate ST4000NM0033 in Raid 0 for now. Runs around 1400 MB/s depending on benchmark app.
 
DJ Meyer said:
depending on benchmark app.
Click to expand...

That's the other important thing to consider here. Some benchmarks and also depending on the type of data and cacheing ability will have rather different benchmark results than other tests and/ or data types.

1400MB/s is pretty good for 8 drives, but it's also a RAID-0.
 
I get these speeds at 90% empty:

12TBRAID10A.jpg


Configuration:
ATTO R608 - RAID10
8 x Hitachi Ultrastar 3TB SAS (HUS723030ALS640)
2 x SNT-3051SS 5 bay internal SAS backplane enclosures. Both operate at 3Gb/s unfortunately, will upgrade to 6Gb/s backplanes eventually. I installed Gelid 80mm fans in each for better cooling.

I went with RAID10 as I get 6 hour rebuilds when a drive goes down vs. 22 hour rebuilds with RAID6. When moving around a lot on set fast rebuilds are a potentially a lifesaver.
 
ARC-1880x hooked up to two 15x3TB disk enclosures (30x3TB total) in raid6. I get about 1900 MB/sec read and 1050 MB/sec write. That is mostly limited by the raid controller though. With a PCI-E 3.0 ARC-1882x I could probably be getting closer to 3 GB/sec read/write.
 
houkouonchi we see the same speeds on our 24 disk and 48 disk DAS RAID's on PCIe 2.0 cards. Almost pulled the trigger on an 1882 today. We don't have as many simultaneous users as in the past few years so the upgrades have really become more of a novelty honestly.

Anyone have luck doing a RAID 10 or 0 with Pegasus J4's and 7200rpm drives? I'm contemplating these setups:

1: J4 w/ 3 1TB HDD and 1 1TB M500 or EVO in RAID 0
2: Pair of J4 in RAID 10 or RAID 0 for ~750+MB/s?
3: 8 2.5" HDD hosted by a PCIe RAID inside a TB chassis
4: Same as above but with 12 drives hosted by an Areca 1880.

I'm looking at these for the rack mount stuff on a Sonnet Echo III with rack kit:
6 drive x 2
http://www.amazon.com/dp/B004G8QERK...TF8&colid=2LLPJP64G5WWK&coliid=I197V6N6A3AZQ3
4 drive x 2
http://www.amazon.com/dp/B004G8QER0...TF8&colid=2LLPJP64G5WWK&coliid=I1EMUW99YZGXA8

I'm strongly considering these because 2.5" means I can swap between the J4's and rack mount kits without worrying about size or weight (I like a slim cart and also do flypack stuff where a 4RU rack has to hold all the essentials. Just unsure of how reliable or fast a Hybrid SSHD RAID would do and if 12 2.5" drives on a nice RAID card is worth the squeeze since I have the 5.25" bays to host 12 of them.
 
I just installed a new 8 drive box on my system (RAID 5), connected via the SAS expander port on the previous box. Getting up to 900 MB/s. I think the slower speed on my old box are just due to it being so full.
 
Jeff Kilgroe said:
My 24TB RAID in a SansDigital SAS enclosure, connected to both external SAS ports on an ATTO R680 is an 8x3TB unit in RAID-5. It gives almost 900MB/s read and 800MB/s write - pretty much the same as the 8-drive Pegasus2. I could also get almost the same speed results connecting two G-SPEED Q enclosure units with 2TB HDDs to the ATTO host in RAID-5.
Click to expand...

Are the HDDs inside that Sans-Digital enclosure connected via a SATA cable to the backplane card(mini-SAS out)?
 
Just wanted to update - I pulled the trigger on another 1880-16 that'll host 12 2.5" drives inside the Echo III-R. I bought a pair of 6 disk 5.25" bay adapters that'll stuff inside the rack kit of the Sonnet. Looks like I'll have to drill into the side of the Echo though to run the internal SAS cables through (sort of a big oversight on their behalf given the 5.25 bays ONLY allow for external cable runs).

I'm torn on the drives though...

12 - 1TB Travelstars in RAID 10 - I don't know if these are fit for Raid 5 or 6
12 - 500GB WD RE drives - These are $150 at the moment but leave me with less than 6TB after some redundancy AND still cost twice as much as Travelstars
2 M500/Evo and 4 1TB Travelstar - For pure speed. Not sure how well these will pair in Raid 5 or 6.

I know the Travelstars aren't fit for big RAID work but I wonder how they'd fair in a RAID 10 given they can better handle 0 or 1 vs Raid 5 or 6. They're so cheap I can stand to buy up 12 or even 16. Asking around everyone says RAID 10 should work fine with the non-enterprise stuff. Any thoughts?
 
The m500's work great in Raid but the Evo's do not. If you go the SSD route get the M500's. 4 in a raid 5 will give you around 1.8GB/s on average an as high as 3GB/s with the right SAS controller.
 
Eric thanks for the insight. Interesting to hear. Have you had any issues with SSD in Raid 5 on particular enclosures? I learned the hard way a J4 can't support 4 1TB M500's. I think it can (from snooping around) support 3 1TB SSD and 1 HHD in slot 1 but I could be wrong. I'm ultimately feeding thunderbolt 2 so unfortunately I won't see more than 1.5GB/s but still good to know. My Areca 1882 could probably see more than that in my old tower but I'm moving away from those.

As a side note - Areca states additional SAS ports can be setup as pass-through including the rear 8080 external. Anyone have luck setting up a controller as both RAID and HBA with regards to reliability and disk mounting?
 
No I have not but that is always dependent on the chassis model since the controller is built into the chassis. Just make sure you get a chassis with an LSI Controller chip and you should be fine. Passthrough on the Areca Controllers has been fine in both regards.
 
Sidebar: what do you mean by passthrough, Eric? Are you saying you can use a card like the 1882 to connect both a RAID and individual drives at the same time (e.g. 6-drive array and 2 RedStations)?
 
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