slow write speeds on LSI RAID controller card

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mac_angel

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running Win7 64bit, 12GB RAM, Core i7 930 stock, 64GB SSD for OS. I have an LSI 9240 8 port RAID card and a 9260 8 port RAID card with 512MB on board RAM. 4 x 2TB 5900 RPM SATA 2 Seagate hard drives and 2 x 2TB 7200 RPM SATA 3 Seagate hard drives, all in a single RAID 5 on the controller card. I've tried both controller cards and I'm getting really poor speeds, especially write speeds, dropping down to 14MB/second writing large video files over. I've ran tests on the hard drives and the RAID consistancy and I can't find any problems. Updated drivers, updated firmware. A friend of mine said it is because of the different speed hard drives, but googling it, all the forums I've seen say the same thing, that the RAID should perform as fast as the slowest hard drives, so they should be about the same as 6 x 2TB SATA 2 5900 RPM hard drives. Anyone have an opinion or any help?
CrystalMark speeds ~225MB/sec read, ~30MB/sec write.
I've also tried installing it into my gamer system. Core i7 2600K OC, 16GB RAM. Same speeds. Tried both sets of cables on both RAID cards. I read online somewhere that some motherboards don't like anything but graphics cards being installed in the PCI-e 16x slots. I've talked to MSI about this and they can't confirm or deny this.
 

mac_angel

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Thanks for getting back to me. I was told that the new firmware and drivers fixed that issue. I also have a 9260-8i, which is a hard drive RAID with on board RAM that is getting the exact same speeds. Even my read speeds are really poor.
 

tokencode

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You'll never get close to 1/2 that speed, those tests were done using 15k SAS drives.. Your drives are SATA and rotating at 1/3 of the speed as the ones used in the test and you're using 1/2 as many disks. Just donig the quick math you should be at no more than 1/6th the speed of those tests. Your results are a little slow, but not an order of magnitude off from where they should be. I run 4x5900 RPM drives in RAID5 and I see approcimately the same speed you do, 30-35MBps and thats on a factory configured NAS device.
 

mac_angel

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yea, I knew that I wouldn't get a speed boost off of the 2 7200RPM drives. I picked them up for the same price as the 5900RPM drives so I figured I'd grab them and swap them out as I do other builds along the way.
Other people seem to think that I should be getting much better speeds than this, including LSI themselves. They don't know why I'm getting such poor speeds. They just keep putting the blame on these being desktop hard drives instead of enterprise hard drives saying that enterprise hard drives have a lot less time out than the desktop hard drives. That I understand, about time out errors. But I am rarely getting them. But they are saying even at the same speed enterprise drives I should be getting a lot faster write speeds.
I also have a HighPoint Rocket RAID 4 port card which the 4 5900RPM drives were connected to. The HighPoint is a pure software RAID card and I was getting close to 200MB/sec write speed on it.
 

mac_angel

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not sure what that is. I know it has 512MB on board on the 9260. I'd assume it would be enabled. It shows in the cards BIOS. The 9240 doesn't have on board cache and is a software RAID. The 9240 and the 9260 is getting the same speed. The RocketRAID didn't have on board cache and was a software RAID card and was a lot faster.
Thank you so much for your help with ideas. I'm pretty technical and used to work at IBM, but I always worked on desktop and laptops. The RocketRAID was my first real RAID 5 set up. It worked great, I just ran out of room and thought the LSI would be better. I should have stuck with HighPoint
 

tokencode

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http://www.lsi.com/downloads/Public/MegaRAID%20Common%20Files/12.12.0-0090_SAS_2108_FW_Image_APP-2.120.243-1482.zip

http://www.lsi.com/downloads/Public/MegaRAID%20Common%20Files/5.2.112_Windows_Signed_Driver.zip

I would try upgrading to the latest firmware and drives to start. The firmware was updated on Jan30th and the driver is from March4th so they're pretty recent. Next download the management utility, you should be able to check to see if write cache is enabled. If you only have read cache or the majority of memory dedicated to read and not write, that could explain the results you're getting. Cache will make a huge difference in performance.

http://www.lsi.com/downloads/Public/MegaRAID%20Common%20Files/11.06.00-03_Windows_MSM.zip
 

kitsunestarwind

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I don't know about your controller but the best write speeds on raid5/6 are obtained when the write cache is enabled, a lot of cards will not let you enable this without having battery backed up cache installed

My 8 disk raid5 array on one of my controllers have terrible speeds with no BBWC , with the BBWC installed it handles large file writes from 70 to 100mb/s
 

mac_angel

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no battery on the RAID card. Yes, there is a jack for it for the 9260. I'm running the latest drivers, firmware, and software. I'm pretty sure the on board RAM is working, though I'll have to mess around and double check. The RAID card also supports Cachecade, being able to also use an SSD for a cache file. I don't mind picking up an inexpensive one, but I want to make sure I'm actually going to get enough speed out of it. This is only for home use, ripping my DVDs and BlueRays to access around the apartment. Once all the movies are on there then I only really need read speeds. But it's taking a long time to put the movies on there.

again, thanks for all the help in trying to trouble shoot this. I'm a tech geek myself, but desktops and laptops. I was a technician for IBM, actually. The HighPoint RAID card was my first dip into a dedicated RAID card. I'm stumped. Does anyone think that it could be the mix of hard drives, 4 x 5900RPM and 2 7200RPM?
 

mac_angel

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okay, I was going to take the day off from this puzzle to relax, but I thought I'd mess around with it for a few minutes. I've been 'forced' into retirement because I have EDS. Think of a bad case of arthritis, so for the past while, messing around with the computers and moving around a lot has killed my knees lately.
Anyway, I just wanted to say that I uninstalled and reinstalled everything. Drivers, Firmware, and software. I'm getting ~235MB/sec read speed and ~175MB/sec. Not perfect, but much better, thank you. Seems like the cache wasn't set up properly. There is advanced software for this as well, but it's not activated. I guess I have to call in to see about that.
 

tokencode

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Be careful if you have no battery backup and you're using the write cache. I HIGHLY recommend putting the battery in place, if you lose power during a write you can corrupt the whole volume. I'd glad things are working better for you.
 

mac_angel

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the computer itself is hooked up to a battery back up, but thanks for your concern and all your help. :)
I'm going to swap out the 5900RPM drives over the next while with 7200RPMs. I'll probably get a good speed boost from that.
Odd thing that happened through my trouble shooting and trying different things, I was actually getting a read speed of ~335MB/sec. I'm not sure what I did that I lost that speed. If I got that speed up then I'd probably get the write speed up as well.
 

FireWire2

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The speed you get from LSI 9240 is slow because it's NOT a hardware RAID card.
Look at the spec... there is NO I/O processor included.

This mean, the host CPU is doing ALL the calculation!
You may said, there is i7 or dual core, quad core CPU, it should be able to handle that...
But you don't really that each drive is sending 1000's of IRQ per sec direct to CPU, which puts a high demand on on CPU clock cycle. On top of that Window won't dedication much of CPU time to assist the RAID engine.

Not even mention: drivers, BIOS, conflict with other card...

As the rule of thumb when come to RAID5 - use HARDWARE RAID, dont cheat yourself with hardware assist RAID such a card

If you need about 200MB ~ 265MB/sec transfer raid then use SPM394 or SPM393

If you need about 450MB or more the use PCIe hardware raid like: ARC-1223-8i
 

FireWire2

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That is incorrect!

It bases on the card raid engine that you used.. some are good some are just plain BAD.

But generalize "RAID 5 is known for it's bad write speeds" is not true. We have RAID5 arrays that read/write over 1100MB/s
 

tokencode

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Actually firewire, I don't care what RAID card you're using, that statement IS true. If you use RAID10 on the same RAID card it will be faster. Yes you can have RAID5 arrays that perform well, but if you used the same number of spindles, you well get better performance from RAID10. RAID with parity calcs (5 or 6) has worse write performance than RAID 0 or 10 with the same number of spindles all other things being equal. Go run a RAID0 on your card and tell me you don't get better write performance..... of course if you are using different hardware your results will be different, but if you isolate just the RAID level, RAID5 is known for it's bad write performance, don't be so quick to say someone is incorrect.
 

tokencode

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well 9 but I get your point, although a 5 spindle (10 drive) RAID 10 will be faster than a 9 spindle 10 drive RAID5 when it comes to writes, that is why RAID 10 is almost always recommended for all databases or other processes that require fast random read/write
 

FireWire2

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Again 10x spindle in RAID5 - Not 9. LOL.
Each drive has 1/N portion dedicates as parity, where N is number of drives
That is why you loose ONE drive in RAID5. Example:
5x drives, each drive has (1/5) 20% capacity taken out
10x drives, each drive has (1/10) 10% capacity taken out
16x drives, each drive has (1/16) 6.25% capacity taken out

So when Read/Write, they all run.

There is NO dedicate parity drive in RAID5. Parity data spreads across among the drives
Think about this, what happen to the raid if the dedicate drives failed (it could happen), then there is NO parity data to rebuilt the volume :)

Matter of fact for Database Server, which has read more write - it will benefit from RAID5 for fast read compare to RAID10

There is lot more on sector, buffer and other stuff setting in raid setting... But if you are correctly using it RAID5 will kick but RAID10 performance.

It matters of how you use/set it
 

tokencode

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That's not correct because not all of the data you are writing is actual data, N-1 is parity data therefore you only see the performance of 9/10 spindles because there is 10 additonal data to write due to parity.

Turst me, go try to run a highly utilized SQL server on RAID 5 and let me know how that works out for you....

Always place log files on RAID 1+0 (or RAID 1) disks. This provides:

better protection from hardware failure, and


better write performance.

Note: In general RAID 1+0 will provide better throughput for write-intensive applications. The amount of performance gained will vary based on the HW vendor’s RAID implementations. Most common alternative to RAID 1+0 is RAID 5. Generally, RAID 1+0 provides better write performance than any other RAID level providing data protection, including RAID 5.


http://technet.microsoft.com/en-us/library/cc966534.aspx

 
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