Which is faster? IDE RAID (2 drives), or a single 15K SCSI Ultra2?

[ncitrdude]

Here is my situation, I'm building a new box using some parts from my current computer. The mobo I've selected is the Asus P4B533E, with integrated ATA133 IDE RAID. I also have an Adaptec 3950U2 Ultra2 SCSI controller from my old computer. I'm wondering if 2 WD 80GB Special Edition 7200rpm IDE drives in RAID0 configuration would be faster than a single Seagate Cheetah 15K rpm Ultra160 drive (ST318453LW) hooked up to the 3950U2.

Storagereview clocks the SCSI drive at 79MB/s max, whereas the WD IDE drives clock in at 49.3 MB/sec max. I couldn't find any tests on the Internet with sustained throughput of IDE RAID setups, so I'm wondering how much faster a 2-drive IDE RAID setup would be than a single IDE drive. I am skeptical that it would be double the 49.3MB/s of a single drive.

My main concern with the SCSI drive is that despite being Ultra160, the controller is Ultra2 (80 MB/s max), and the Asus mobo has only 32bit/33Mhz PCI slots, so the entire bus is limited to 133MB/s (I think, correct me if i'm wrong?). There will be no other cards plugged into the PCI slots, so the SCSI adapter card would pretty much have sole use of the PCI bus (aside from the integrated sound and LAN).

So basically, would the Cheetah's 15,000rpm rate and lower seek times coupled with the 80MB/s limit of the adapter card and 133MB/s limit of the PCI bus make it slower than a 2-drive IDE RAID setup? Any insight or opinion is greatly appreciated. Thanks in advance...


Jason

 

[Viper96720]

The raid may be faster sometimes but scsi can read/write simultaneously and ide can't.some raid results

 

[Smilin]

You hit the million dollar question.

I just went from an Ultra2 SCSI setup to IDE raid. I think it's a tossup. That seagate drive will pull off faster seek times but sustained throughput should be about the same as the raid. Basically the difference is going to take a benchmark to measure. It's going to be close enough that you won't be able to tell with the 'naked eye'. To answer one of your questions: The raid solution really is just about double the speed of a single drive. I'd say the throughput is going to be about 190% of a single drive.

Some other things to consider:
You won't have this setup forever. On your next purchase will you be itching to upgrade the SCSI controller? If so it's gonna cost. If not, you've blown your investment in the seagate drive. Raid wins here. Mind you your new controller sometime down the road my be a SCSI raid controller...not much more than a plain SCSI controller.

Drive space. Speed aside, what kind of storage do you get for your money? Raid wins here.

Reliability. SCSI is going to win here. You know the story with raid 0.

Money. Over the long term having a SCSI solution is just plain expensive. This is what made me switch.

Things NOT to consider:
The limitations of your PCI bus and Ultra2 controller aren't going to make much difference. Your burst speed will get clipped a bit is all.

 

[CurtCold]

IT's going to be fast enough your not going to notice the diff between the 2. Here is a good review of the drives for you RAID REVIEW


Hope that helps you out. Both are sweet, but less risk of loosing your data on the scsi than the raid 0 though

 

[Grminalac]

Well i have 2 WD1000JB drives on a Fastrack 2000tx and I was impressed with the performance. Just using Sisoft sandra disk benchmark my setup garnered a score of 49000 (stripe size of 512k) while it showed the score for two 15000k hard drives pulling in about 46000. So going by Sandra the two WD drives should be faster.

 

[JimKiler]

Seagate 15K review at Toms

According to tom's the Seagate is incredibly fast access but your raid will beat it in maximun date transfers.

 

[Dug]

You are also talking about a Seagate that isn't available for purchase yet.

That 79MB/sec is for the 15.3k drive. You would have to wait for its release. The WD's you can get right now.

And what's the max throughput your Ultra2 SCSI card can handle?

 

[ncitrdude]

That seagate is available now. It's at newegg for around 219 i believe...

jason

 

[Dug]

That seagate is available now. It's at newegg for around 219 i believe

Your right. Sorry about that. Only 18g's though for $200. That will fill up real fast.


edit: they are 80pin only- I wouldn't bother with a 80pin to 68pin converter.

 

[ncitrdude]

Why's that? Is there a performance hit if using a 80-pin to 68 pin converter?

jason

 

[Dug]

Tell ya what - head on over to storagereview

goto the forums and read about scsi performance and Windows2k and XP.
You may not want scsi after reading through everything.

 

[Sunner]

If it's between the 15K.3 and 2X WD 800JB, then it's an easy choice.

The 15K.3 will outperform the WD's without breaking a sweat in most cases.

It's seek/write times are FAR better(more than twice) compared to the WD's.
It's reliability will likely be better than a single WD drive, based on the fact that SCSI drives generally are more reliable than IDE drives, and with RAID-0 you'll effectively double the chances that things will go wrong.
Im betting transfer rates will be better on avarhe on the 15K.3 as well, RAID is a but like SMP, 2x1000 doesn't make 2000, and two drives that peak at 50 MB/Sec doesn't make 100 MB/Sec.