CarZin

yet another scsi performance issue

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I have the same board a user in a blow thread has. The Gigabyte 8KNXP-Ultra Rev 2. It has an onboard u320 controller. This controller operates on a seperate PCI bus which is rated over 500 megabytes/sec (so, I am not limited by the standard PCI 33 Mhz bus).

I have 3 Maxtor Atlas IV 36gig drives. They are 80 pin hard drives, and are being converted to 68 pin by EXPENSIVE adapters rated for u320 (like $35 a piece). So, I am not using cheap ebay junk. I am using an LVD/SE cable, and the cable is properly terminated.

I Think I am affected by the XP bug, so tell me what you think

1) When I had a 2 drive RAID 0 stripe with the 3 drive set as a spare, I was getting the following numbers:

on the RAID 0 array I was averaging about 90 megabytes/sec read, bursting to 110.

on the SINGLE SPARE, I was averaging about 60 megabytes/sec read.

2) When I created a 3 drive stripe set, my numbers did not change for the stripe. Still averaging about 90 megabytes/sec.

3) I have used a lot of different tools. One of the tools I saw very weird results in was DiskSpeed32. On some boots (when I had a 2 drive stripe), the thing was showing 3.5 ms access time, and average transfers of 180 megabytes/sec. That just seemed bogus to me. Yet on other boots, I was seeing the 90 megabytes/sec (which seemed to be confirmed from other programs. I thought this was crap, until I had PCMark HD benchmarks vary from 2000 to 3500. Maybe this is nothing, maybe it is something.

So, does it look like the XP problem, and that I need to use 2000, or is something else going on?

Thanks!

Ryan

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1) When I had a 2 drive RAID 0 stripe with the 3 drive set as a spare, I was getting the following numbers:

on the RAID 0 array I was averaging about 90 megabytes/sec read, bursting to 110.

on the SINGLE SPARE, I was averaging about 60 megabytes/sec read.

2) When I created a 3 drive stripe set, my numbers did not change for the stripe. Still averaging about 90 megabytes/sec.

These scores are great for two drives and a single drive. Most are getting below 50 MB/s. Why do you have a spare on RAID 0? It will not fail over unless you have RAID 10, 5, 50, or 1. RAID 0 will not fail over to spare. 60 MB/s is the sustained speed of a SCSI U320 drive.

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^ Correct. The only reason the spare existed is that I found during the building of my machine that one drive went bad. I had to create a 2 drive array while Maxtor sent me a replacement. It didnt matter that I was going to have to reinstall everything again, because I knew it was going to take a few installs before I got everything how I wanted it.

Problem

My numbers SHOULD increase when I add the 3rd drive. As it stands, the performance of the 3 drive array is exactly the same as a 2 drive array. Something ain't working.

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Primary difference that affects me is the bus speed available for the onboard controllers.

On Rev 1, the bus speed for the u320 controller is about 260 megabytes/sec. So, if you had enough drives to saturate the 320 bus, they would hit the 260 ceiling.

On Rev 2, the bus speed for the u320 controller is over 500 megabytes/sec. So, given the same scenario, your bus speed would not limit your u320 performance with a lot of drives.

That was the entire reason for getting this board. I did not want my harddrive data saturating the PCI bus that everything else shared, and I certainly didnt want to be limited on the transfer. I can't figure out what the hell is happening. I am going to install Windows 2000 Server tonight and see how that works out. I will post results since you have been having issues.

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CarZin, we have the same problem.

I own the Gigabyte 8KNXP ultra board (But I think it is rev1 version), and I do have some problem with my Maxtor Atlas IV 10k 68 pin 73GB disk and Windows XP professional SP1

Let me guess, you're experiencing some problems with the reading speed of your disk, Windows XP loading screen appears for much time, applications takes a ridiculus big time to load and let's not talk about the writing issues.

I didn't knew there was a rev2 of this motherboard, so I'll contact Gigabyte to see if I can correct the 260 Mb/sec speed with some kind of BIOS upgrade or something like that.

Meanwhile I'll try Windows 2000 pro SP1 and then SP2.

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Well, you seem to have a worse situation that me. (if I recall your posts)

I saw your numbers, and they werent pretty. On a 2 drive RAID 0 stripe, I am getting a solid 90 megabytes/sec on the read, with bursts to 115. The problem is that I am getting the same thing with 3 drive stripe set, so something is bottlenecking....

My loading is still very fast, and faster than the raptors I have seen, but not as fast as they are supposed to be.

I know everyone asked you this, but are you sure you are using u320 rated adapters (80 to 68) on your drive? ALSO, on startup, does your array initialize as 'Optimal'? My adapters were about $35 a piece from the company that was the first to make them. They stand behind the quality, and guarantee it to work with the full u320 bandwidth (LVD/SE).

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I do not need to use 80 to 68 adapters because my disk is 68-pin, about the SCSI cable I'm using the cable that came bundled with the motherboard so I guess it is U320 LVD/SE capable.

On the other hand I'm not using any type of RAID, I'm using my disk as a single drive.

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One more thing, what tool dtermines if my disk is working in LVD or SE mode??

not sure if it works on XP, but Adaptec SCSI tools (does not have to have an Adaptec chip)

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2000 was not likely to make any difference. You claim to have read performance issues and the 'XP SCSI bug' affects write performance only.

What benchmark are you using? I strongly recommend you test your transfer rate with Winbench 99.

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