ATTO on Raid-0

scott

Hi Guys
I am getting a little closer to getting my new P4 rig where I want it. I ran ATTO on the raid array and they seem low. While I am quite happy with the way the machine runs, If I could get a little more performance from the array I would be real happy. The controler is on the mobo.
Any suggestions?

Mt_Goat

Why such a large stripe? What cluster size? Have you tried tweeking the latency yet? Spill the beans on all the specs on just the array.

scott

I chose the large stripe size as the "performance" option in the raid setup utility. the cluster size is 4kb with 8 sectors to a cluster.I have done nothing with the latency. What else do you need to know?

Scott

Tex

For most ide drives that stripe is way to large and you usually do better with a bigger cluster size also. If not equal to the stripe then no more then 4 x cluster to get stripe size.

usually the wd's like closer to a 16k or 32k stripe and a 8k to 16k cluster size to get maxed atto scores. Thats said the scores for those drives are not bad either. Just a little low. I would bet a hundred bucks right now I could tweak them to the very max and you won't "feel" any differance at all.

If you already have the os on those drives then you might stick to just modding the cluster size and trying to raise the latency of the controller a bit to raise the writes a tad.

Cheers

tex

scott

Thanks guys

Yes there is an OS on C: but there are two other volumes partitioned. Powerstripe would not let me access latency of the controller. It reads 0 and is grayed out. ( the read only box was unchecked ) As I said, I am pleased with the way it runs so I will probably just leave it alone.

Thanks again

Scott

Mt_Goat

Most folks used to get the best all around results with 16 stripe/16 cluster. With the advent of newer controllers and different HD's there has been some experimenting to what works best in someones particular system. I myself found that both of my arrays with WD SE drives prefer to be run with a stripe size of 32. My array with 2 WD1000JB HD's in RAID-0 on a HPT 1520 controller like a cluster size of 8 so it is 32/8. My array with 2 WD 60JB HD's in RAID-0 on the onboard Silicon Image controller like a cluster size of 16 so it is 32/16. I have another computer with 2 Maxtor HD's in RAID-0 on an onboard HPT 372 controller that just loves 16/16 and coughs at most other configs. I recomend experimenting with all the different combinations you can. I like to start at 16/16 and try all the different clusters on thae 16 stripe; ie 16/16, 16/8, 16/4. Then I go with 32/32, 32/16, 32/8, 32/4. Then try 64/64, 64/32, 64/16, 64/8. The larger the cluster size the more disk space you will use and won't be as space efficient. I didn't mention using less that 16 stripe as it uses more processor useage so as not to be as high of performance. I also never use a cluster more than 1/4th my stripe size as it won't do any good. It is important to do a full format when changing sizes. DO NOT USE THE "QUICK FORMAT" OPTION. When running ATTO I like to average the results of at least 5 runs and make sure you have nothing else open.

The next thing after you find a stripe/cluster with the best level of performance is to adjust the PCI Latency of your controller. For this I use A tool called Powerstrip. Once you have it installed you will need to open it, which puts an icon in your toolbar. Right click the icon go to: Options>Adapter Information.


Next you need to:

1. Scroll through the device list till you find your controller.

2. Uncheck the box marked "Read Only".

3. Adjust your latency. Try eferything between 32 and 248.






Here is an array prior to latency tweeking:



Here is the same after:

scott

mtgoat
we must have been typing at the same time. Here is a screenshot of powerstrip. Does this mean Intel has locked out the ability to tweak? Or did I miss something somewhere.

Mt_Goat

No it doesn't. If you click on the box where the checkmark is it will go away and you can apply changes. After you make a change you will get a dialogue asking if you want to apply, click, yes. As soon as you do that another will ask if you want the changes to be remembered every time Powerstrip starts, check no untill you find the one you want to keep. Then make sure you go into the Powerstrip options and check the box to start it with Windows. Read through my details above. There is a lot there.

scott

In the screenshot I attached my cursor was over the box . Anyway it is unchecked. I can make changes to anyother device it lists. Unless it says Intel in front of it, then the option is grayed out. i.e. Intel USB, Intel ethernet, Intel SMBus etc,etc. Sound card and video card are tweakable

Scott

Mt_Goat

scott said
In the screenshot I attached my cursor was over the box . Anyway it is unchecked. I can make changes to anyother device it lists. Unless it says Intel in front of it, then the option is grayed out. i.e. Intel USB, Intel ethernet, Intel SMBus etc,etc. Sound card and video card are tweakable

Scott

OK now I see. I was unaware you had an actual Intel mobo. If it was one from Abit, Asus, MSI, Soyo or one of the other mfgrs you have been able to do it. You can still try different combos of stripe/cluster. As Tex mentioned, try the 16/16, 16/8, 32/32, 32/16 and 32/8. Does you rboard have an option in the bios for PCI Latency? If so, you can try it there but only work between 32 and 128 as it will affect other things. The other option would be to get an add-on RAID card made by HPT.

scott

Thanks I will check it out

Scott