Bandwith vs modern raid arrays
After picking up 3 WD Raptor drives, i was all excited to see what kind of speeds i could get with them. I hooked them up to a Striker2 formula board with the 780i chipset in a RAID 0 array, fired up windows to do some benchies and was fairly dissapointed...
My first test gave me 140MB/s I was expecting to see alot more with 3 raptors, so i started cruising the net to see what i should be getting. I really didnt find any numbers for 3 drives, and no amount of searching found me any answers.
I thought maby it was just the nvidia chipset that was slowing it down, so i put the drives into my asus p5k with the P35 chipset, and that didnt fair much better @ 135 mb/s
I had a PCI SATA controller kicking around so i stuck that in for another benchmark of about 100mb/s with raid 0, so that was pretty useless.
After talking to a fella at the local shop, he suggested using a better add on card and sold me a Rocket Raid 1740 PCI raid card, i took that home and was Extreemly dissapointed at the results of a mere 100mb/s... obviously its wasnt the el cheapo sata card i had that was slowing it down, but the bandwith of the pci bus itself.
After consulting with the dude at the shop again, he was kind enough to loan me a 2 port pcie 1X raid card, it gave me 135mb/s with just two Raptor drives, so now i was really sure that the mobo was somehow limiting these drives.
By now a couple months have gone by with little success with these drives, and it was really dampening the joy of my new pc, so i decided to make the jump to a full hardware raid PCIE 8X Rocket Raid 3320 Raid card.
Before i go any further i just want to mention another snag i came across when i got the RR 3320.
My system is using SLI, so obviously i have to have a TRI SLI Capable motherboard to have the PCIE card installed, The striker2 formula is tri sli capable, but when i plugged the RR 3320 into the 3rd slot, the bios would be there at boot, but would not detect any drives. I put the RR 3320 into my P5K to see if the card actually worked, and it detected the drives perfectly, so i removed a single Video card from the Striker and tried the card in there, and it detected it fine there too. So i had to decide which was more important to me, SLI or Raid... I chose an EVGA 780i motherboard. I've hated that Striker2 formula since the day i bought it. its never ever ran properly, didnt overclock even proven cpus much past stock, wont run my Q9450 cpu at all, even though its officially supported... This was the last straw.
After getting the mobo replaced, and everything back together, SLI as well as the RR 3320 card, It booted properly, detected the drives and i was back in business.
The results of the HDtach test were like a breath of fresh air. 260 mb/s Finally the Raptor drives could realize their full potential.
Considering the amount of time, Effort and money, that i put into getting these drives to their full potential, not to mention the lack of good information i could find on the net, i decided to post my findings here. I took some screenshots of the benchmark results with the onboard nvidia 780i Raid 0, the pci rocket raid 1740 and the PCIE Rocket Raid 3320.
Thats when i found out that my story wasnt really done....
While doing up some screenshots of the benchmarks (since i didnt bother when i first started researching) I came across something else that was interesting to note...
Now i mentioned already that i replaced my striker2 with an EVGA motherboard, so naturally i did all the screenshot tests on the EVGA board. Id always assumed that it was the chipset that was slowing down the raid, but apperantly this wasnt true. I recieved a pleasant surprise while running the benchmark for the onboard raid, when it came back at 200mb/s Both the Asus P5K and the Asus Striker 2 Formula motherboards topped out at less than 140 with onboard raid 0. Now i can only assume that it wasnt the chipset, but the motherboard itself that was limiting the bandwith.
If only i had an EVGA Mobo to start with, i could have been content with 200mb/s, and saved myself 400 bucks on the raid card... not to mention the 350 bucks on the striker...
here are the screenshots
This is the ONBOARD Raid 0
This is the PCI Rocket Raid 1740 (notice that its topping out at 110mb/s, neither Asus boards broke 100mb/s with pci raid.)
This is the PCIE 1X 2 port raid card with (obviously) only 2 Raptor drives (please excuse the quality, i took the pic with my camera phone, and is the only screenshot i have of any of the first tests)
This is the PCIE 8X Rocket Raid 3320 (Notice the MASSIVE increase in burst speed. Might have something to do with the 256mb of ecc ddr2 this card has onboard.)
This is the Rocket Raid 3320 in raid 5, just to show the performance difference between raid 0 and raid 5
Why i think this information is extreemly important to enthusiests...
Most modern hard drives these days will give you around 100 mb/s read speeds, the high end ones around 130 mb/s so its pretty easy to see that even just TWO modern drives in a raid 0 array have the potential to max out your motherboard's bandwith, put 3 drives on and your wasting their potential. For sure a SINGLE Velociraptor would max the bandwith of the Asus P5K Sata bus.
(Dont think modern drives are capable of Raptor speeds? Heres a single 500gb WD drive i bought for 140 bucks)
Recap on my findings
Asus P5K p35 onboard raid = 135mb/s
Asus Striker 2 Formula 780i onboard raid = 140mb/s
PCI Rocket Raid 1740 = 100mb/s
PCIE 1X (unknown) raid (only 2 drives) = 130mb/s
EVGA 780i onboard raid = 200mb/s
PCIE 8X Rocket Raid 3320 raid = 260mb/s
I hope this information is useful, i've spent more getting the full potential of these drives than most people spend on their entire computer, hopefully it can prevent you all from making the same mistakes that i did. I decided to go with the very expensive 8X PCIE card, but i would think that a much less expensive 4x card would have the bandwith you would need for any raid array that has more than 2 drives.
High Point RAID controllers are the worst controllers in the world. The only thing worse than High Point is nVidia onboard RAID. AFAIK first gen Raptors are garbage (relative to today's 7200RPM drives).
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