Overclock.net › Forums › Components › Hard Drives & Storage › RAID Controllers and Software › PERC 6/I reads slower than it writes?! RAID 6, Four 2tb disks
New Posts  All Forums:Forum Nav:

PERC 6/I reads slower than it writes?! RAID 6, Four 2tb disks

post #1 of 5
Thread Starter 
Hello everyone.

I recently picked up a PERC 6/I integrated card and am attempting to get it up and running at full speed but I'm running very short on ideas.
Lets say that a different way. I'm getting CRUSHED by this thing here. I'm pretty much out of ideas and need some guidance from you guys.

System Details:
Asus M4A78-E
AMD Phenom II X4 945
8gb ram
Onboard Video, perc is in the Blue 16x slot

OS Details:
Win 2008R2 is the OS. I'm NOT booting off the RAID.
Default driver baked into win2k8r2.
MegaRaid Storage Manager 13.04.03.01

PERC Details:
Firmware package: 6.3.0-0001
Firmware Version: 1.22.12.0952

Raid Details:
2 Samsung F4 HD204UI
2 Seagate warranty replacements for a couple bad Samsungs - ST2000DL003
Strip Size: 64k (I have large files and small)

IO and Cache Policies:
Disk Cache Policy: Enable
Read Policy: Always Read Ahead
IO Policy: Direct IO
Write Policy: Force Write Back without BBU (one is on it's way)

Symptoms:
Every benchmark I throw at it shows terrible read speeds from the array - but write speeds are good. Actually they're BETTER than the read speeds?! I've set the block size in HD Tune to 512k (and higher). The read speeds are all over the place.


512k block size:




Things I've looked at:
Is the Raid fully initialized? YES
Background processes: NO - looked in MSM and at the raid bios level
Maybe a bad cable set?: NO, swapped with the other SATA breakout cable set I bought
PCIE slots being dumb?: Maybe? I put the card in the blue slot 16x with the "VGA Switch Card" in the black slot. I tried without the switch card which should put both slots at 8x. I tried in the black slot. All deliver the same performance.
Maybe the onboard raid is somehow messing with the PERC? Set to IDE mode for all onboard SATA ports

So, what am I missing? A bios setting maybe?

How can I confirm further? Move the whole perc and array into another machine to see if the performance is still bad for that drive set?

Pull one drive at a time and benchmark them individually? I did this prior to putting them in the raid, each drive seemed fine with around 130MB/s peak rate.

Any ideas are appreciated. thumb.gif
post #2 of 5
I found that with my perc 5 and 6 that even when set to write back without bbu it never seemed to work properly.

firstly confirm firmware revision on the card, make sure its upto date.
Gaming Rig
(12 items)
 
Main Server
(13 items)
 
 
CPUMotherboardGraphicsRAM
Intel i5 2400k Asus P8H77-M Onboard HDMI 16GB Gskill Ripjaw 1600 
Hard DriveOSMonitorPower
6x Sammy 2TB F4 (Perc 5i On LSI Firmware w/BBU) Windows Hyper-V 2008 R2 32" LG 1080p LCD via HDMI OCZ 700W Modular 
Case
Fractal Designs R3 
  hide details  
Reply
Gaming Rig
(12 items)
 
Main Server
(13 items)
 
 
CPUMotherboardGraphicsRAM
Intel i5 2400k Asus P8H77-M Onboard HDMI 16GB Gskill Ripjaw 1600 
Hard DriveOSMonitorPower
6x Sammy 2TB F4 (Perc 5i On LSI Firmware w/BBU) Windows Hyper-V 2008 R2 32" LG 1080p LCD via HDMI OCZ 700W Modular 
Case
Fractal Designs R3 
  hide details  
Reply
post #3 of 5
Thread Starter 
I'm on the latest Dell firmware 6.3.0-0001.

Write speeds change drastically if you change from WT->WB so I believe that option is working properly.

I'm not too concerned with the write speeds. I think they're fine. I'm looking specifically at the read speeds which are less than a single drive by itself.
post #4 of 5
Thread Starter 
You know what, 6.3.3 seems to be the latest I can find online.

I'll update it when I get home. I sincerely hope this fixes the issue for me.
post #5 of 5
Thread Starter 
Well the new firmware did nothing to improve read speeds.

Any other ideas?
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: RAID Controllers and Software
Overclock.net › Forums › Components › Hard Drives & Storage › RAID Controllers and Software › PERC 6/I reads slower than it writes?! RAID 6, Four 2tb disks