So how fast would 4 hd's in Stripe-0 mode be ?

Kazer · Post by **Kazer** » Fri Jun 28, 2002 8:50 am

From what I've read the Western Digital Special Edition 8MB Cache hard drives have outperformed some raid setups. So my question is, how fast would 4 WD 8MB hd's be compared to a single WD 8MB hd ?

Does raiding 4 hd's give a better performance boost than 2 hd's raided ? If so is it by a lot ?

Busby · Post by **Busby** » Fri Jun 28, 2002 9:39 am

What RAIDing HDs does is lowers your access time and increasing read rates. The 8MB cache allows for higher sustained transfer rates. So therefore a RAID array w/ 8MB cache drives would be super fast. I mean my RAID array w/ dual 60GB ATA133 Maxtor drives is already fast enough, I couldn't imagine it with the 8MB cache WD drives. As to 4 or 2 drives. I would suggest doing 2 seperate RAID arrays if you go 4 drives. The reason is the IDE bus can only access 1 drive on the channel at a time. That is why when doing a RAID array w/ 2 drives you put them both as masters on different IDE channels. So if you do 4 drives, in my opinion 2 seperate arrays, 1 with Master1 and Master2 and number 2 with Slave1 adn Slave2 that way you will still get full preformance given the way IDE is. 2 drives would be plenty though.

DocSilly · Post by **DocSilly** » Fri Jun 28, 2002 9:51 am

- "increasing read rates" : YES
- "lowers your access time" : NO

RAID-0 increases only your STR (sustained transfer rate), adding a drive to an array increases STR but the PCI bus limits the max. STR to around 100MB/s. Storagereview reviewed the WD 8MB drives, the last one was the WD800JB, lowlevel measurments show STR from 29-49MB/s (quite impressive for an IDE drive), so 2 drives in RAID-0 would already be enough to saturate the PCI bus. You would only increase size when you add more drives to a RAID-0 array but not anymore performance.

Kazer · Post by **Kazer** » Fri Jun 28, 2002 10:15 am

Thanks for the info guys.

I was gonna go with a Abit AT7 motherboard and have the 4 hd's on the 4 diffferent ide raid ports. So that they would all be master. If I did that I would get better performance that 2 hd's raided correct ?
Then just setup my DVD drive and CD-RW drive on the 2 non raid ports so everything would be master.

Abit went nuts with the AT7, you can hook up 12 hd's if you wanted to.

PreDatoR · Post by **PreDatoR** » Fri Jun 28, 2002 11:36 am

The only way your gonna see much gain with 4 HDD's in Raid 0 would be write times... It can only access 1 HDD at a time on the channel so i don't see it as having much of a performance increase over 2... If ya have the drives might as well try it... I've got 2 Maxtor D740x 20 giggers in Raid 0 and i can't see it as being much faster than it already is...

Busby · Post by **Busby** » Fri Jun 28, 2002 1:42 pm

I thought your access times were lowered, oh well guess I was wrong. So is an average of 35906.0kps in HD Tach good for a RAID0 array?

All I know is I love my RAID. Formatting, defragging, copying files, they all take less time. I had a 96GB partition and it would defrag in about an hour or so, if it was a single drive i've heard of it taking a whole weekend.

Busby · Post by **Busby** » Fri Jun 28, 2002 1:47 pm

BTW if you are using a VIA chipset goto http://www.viahardware.com and to the forums and look for George's PCI Latency Patch. The latest BETA version of .20 gives the best preformance, at least on my mobo and I have benchs to prove it.

PreDatoR · Post by **PreDatoR** » Fri Jun 28, 2002 2:06 pm

Busby in HDtach i'm scoring 47k transfer rates with my 2 20 giggers... something don't sound right on yours... I got that score downloading at 100k/sec also. I'm gonna install the patch and see if the scores pickup... oh course i'll do this with the hdd's idling and not doing nothing htough...

Was just thinking doesthe stipe/cluster size affect the speed any cause i'm running a 16k stripe and 16k cluster on this 8K3A+

Also you tried deleting the hptpro.sys files... Just search your hdd rename those files to .old... That helped my scores out a bunch...

Busby · Post by **Busby** » Fri Jun 28, 2002 9:47 pm

Oops my signature isn't updated. I'm running a Promise PCI FastTrak TX2000 RAID card. Stripe and cluster size make a BIG difference on preformance from what I have read. I'm using a 64K stripe size and whatever size default NTFS does. I probably so redo my array but I have so much stuff I can't back it all up without burning millions of CDs.

PreDatoR · Post by **PreDatoR** » Sat Jun 29, 2002 12:43 am

Still should be gettin' a lil better raid scores than that. NTFS defaults to 16k clusters so thats probably what yours is... next time you format might wanna go 16k strip... its nice

Busby · Post by **Busby** » Sat Jun 29, 2002 12:56 am

Stripe can only be changed via recreation of RAID array. I am going to do that. Just gotta copy ~11GB over my 802.11b network, this was after I deleted about 30GB of stuff

Busby · Post by **Busby** » Sat Jun 29, 2002 2:54 pm

:

:up :B

:+ )*
:chicken

My RAID array now is set to 16k stripe and 16k cluster and well, 53916.9 kps average in HD Tach with a maximum of 85748.0 kps. Now this is fast!

rool

PreDatoR · Post by **PreDatoR** » Sat Jun 29, 2002 3:39 pm

Now that looks a lot more like it