What's the practical difference between PCI-X and PCI SATA RAID Controllers?

[HeroOfPellinor]

I plan to use 6 80GB WD Caviar SATA drives and a pair of 36GB Raptors. Maybe 4 and 4.....I haven't decided yet.

In any case. Is it an absolute requirement to go with a raid controller that uses PCI-X or would PCI do fine?

 

[windraider]

uhmm.. either will "work" just one will be way better.
PCI-X has much much more bandwidth than PCI, so for large raid arrays pushing lots of data it's better to go with PCI-X, PCI will work it will just be much slower.

PCI = 32 bits X 33 Mhz = 133 MB/sec
PCI-X = 64 Bit X 66 Mhz, or 100 Mhz, or 133 Mhz.... = 528 MB/sec, 800 MB/sec, 1064 MB/sec... (math seems a bit off today.. but those are pretty close to the actual bandwidth speeds..)
i think the new PCI-X specs up the speeds to 266 Mhz and higher..

PCI-SIG on PCI-X for lots more info.
hope this helps some.
Cheers

edited for grammer/clarity

 

[biostud]

Don't use different drives for RAID, the size and speed will match the smallest and the slowest drives

 

[Vegito]

before you go out and buy.. do you have pci-x slots ?

 

[Markfw]

Yes, very few motherboards have PCI-X. The only ones I could find were all duallie motherboards, so thats the way I went. But for 6-8 drives you would need the bandwidth to properly use all the drives speeds (if you went raid 0 or 5)

 

[HeroOfPellinor]

Originally posted by: biostud
Don't use different drives for RAID, the size and speed will match the smallest and the slowest drives

I'm planning to have 4 separate volumes with raid1.

And, yes, I have a nice $400 dual opteron board picked out with a 133 PCI-X slot. Planning to go with that Broadcom/Raidcore 8 channel card.

 

[ChicagoPCGuy]

Originally posted by: HeroOfPellinor

Originally posted by: biostud
Don't use different drives for RAID, the size and speed will match the smallest and the slowest drives

I'm planning to have 4 separate volumes with raid1.

And, yes, I have a nice $400 dual opteron board picked out with a 133 PCI-X slot. Planning to go with that Broadcom/Raidcore 8 channel card.

Without a doubt PCI-X is the only option for high performance here. That is why the higher end server boards have these slots--specifically for RAID cards and dual and quad port Gigabit ethernet cards as well. You do NOT want either of those devices on the very limited PCI bus. There is another board--the DFI 855GM (?) chipset based board that accepts Pentium-M Dothan-core CPU's for desktop machines that also has a PCI-X slot. Why a PCI-X slot on a Pentium-M desktop board? Heck if I know.