VERY slow RAID5 on ICH10R with WDC Green series

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benzebut

Junior Member
Jul 4, 2011
21
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0
Hi,


I'm having really slow write speeds when copying files.
It starts at ~120mb/s and goes down to ~5mb/s


I'm running windows 7 ultimate x64 with latest intel rapid storage driver v10.1.0.1008
Here's my rig
Gigabyte P55-UD3R
Intel core i7 860
4x2gb gskill's ripjaws ddr3 1600mhz cl7
1x 60gb OCZ Vertex 2 for OS
3x WD20EARS version 00MVWB0 with firmware 51.0AB51 (poor raid5)
3x WD10EADS version 00M2B0 with firmware 01.00A01 (poor raid5)


Is there something i'm missing?
How can i test my stuff more further?
are there any optimisations i could try?


Also, i have read a little about TLER not being present on WD green series. Would that affect performance as much as that?
Maybe i should return some and use another brand or model? Any recommendation?
Thx alot
 
R

RaiderJ

Diamond Member
Apr 29, 2001
7,582
1
76
You're running two RAID5 arrays? Software RAID5 is typically very slow, and if you're running two of them that makes it even slower I'd imagine. From what I understand, those drives can cause problems in a RAID5, but not the performance type issue you're seeing.
 
boochi

boochi

Senior member
May 21, 2011
983
0
0
This has nothing to do with the drives being green. RAID5 should be run with a hardware raid solution and not onboard software RAID.
 
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benzebut

Junior Member
Jul 4, 2011
21
0
0
boochi said:
This has nothing to do with the drives being green. RAID5 should be run with a hardware raid solution and not onboard software RAID.
Click to expand...

With that in consideration ive done some research seemed to be like an ok cheap alternative to use intel rapid storage/ich10r raid5 but is it THAT bad?

With 3x seagate barracuda 7200.10 250gb drives in same raid5 scenario i get much much much much better performance.
 
Gillbot

Gillbot

Lifer
Jan 11, 2001
28,830
17
81
benzebut said:
hi,
can you enlighten us why?
Click to expand...

The variable spin feature and TLER.

As a non-TLER HDD fills up with data, the error detection firmware
might take too long, and the RAID controller may drop that HDD
from a RAID array.
Click to expand...

IntelliPower.
A fine-tuned balance of spin speed, transfer rate and caching algorithms designed to deliver both significant power savings and solid performance.
Click to expand...

I have used them myself in Raid, they do WORK but the performance hit can degrade them to the point that a GOOD single drive may outperform them.
 
R

RaiderJ

Diamond Member
Apr 29, 2001
7,582
1
76
benzebut said:
With that in consideration ive done some research seemed to be like an ok cheap alternative to use intel rapid storage/ich10r raid5 but is it THAT bad?

With 3x seagate barracuda 7200.10 250gb drives in same raid5 scenario i get much much much much better performance.
Click to expand...

If different drives give you much better performance, then it definitely sounds like those WD Green Drives are your performance issue. The TLER aspect is frustrating, as it seems like WD is intentionally causing that issue to force people to buy their enterprise drives for RAID.

What about running a couple drives in a RAID0, then having another set mirrored to act as backup? Seems like if you can avoid the RAID5 issue you'd be fine.
 
M

Mark R

Diamond Member
Oct 9, 1999
8,513
16
81
RAID 5 is very demanding on a good quality RAID subsystem design, with large caches and sophisticated read/write scheduling.

Without highly tuned algorithms and lots of memory, the write performance of RAID 5 is catastrophically bad. Typically Mobo controllers use the most basic scheduling algorithms and minimum RAM possible.

Advanced software RAID 5 will give much better performance, by being able to dedicate large amounts of RAM for stripe caching, and by using careful scheduling, including delayed partial stripe-writes.

There is only a limit to the number of optimisations that can be performed in RAM, due to the need for power-failure (or OS crash) safety. Only hardware RAID cards with battery/flash backed RAM caches can offer these aggressive optimisations without the risk of rendering your array irrecoverably corrupt after a crash.
 
Gillbot

Gillbot

Lifer
Jan 11, 2001
28,830
17
81
Engineer said:
That's a myth. The drives operate at one fixed speed (unless something has changed over the last year or so).
Click to expand...

tell that to western digital, the intellispin feature was pulled from their green drive spec page and is listed with tler as to why NOT to use them in raid.
 
B

benzebut

Junior Member
Jul 4, 2011
21
0
0
Mark R said:
RAID 5 is very demanding on a good quality RAID subsystem design, with large caches and sophisticated read/write scheduling.

Without highly tuned algorithms and lots of memory, the write performance of RAID 5 is catastrophically bad. Typically Mobo controllers use the most basic scheduling algorithms and minimum RAM possible.

Advanced software RAID 5 will give much better performance, by being able to dedicate large amounts of RAM for stripe caching, and by using careful scheduling, including delayed partial stripe-writes.

There is only a limit to the number of optimisations that can be performed in RAM, due to the need for power-failure (or OS crash) safety. Only hardware RAID cards with battery/flash backed RAM caches can offer these aggressive optimisations without the risk of rendering your array irrecoverably corrupt after a crash.
Click to expand...

Is there any way to edit the intel ich10r controller(or gigabyte's xhd) to use more ram or/and different settings? Otherwise can you suggest me a good raid software for raid5?

Keeping in mind that my green drives dont have the error reporting timeout option (TLER) Is it worth buying a cheap raid controller supporting minimum 4 sata drives?
 
Engineer

Engineer

Elite Member
Oct 9, 1999
39,230
701
126
Gillbot said:
tell that to western digital, the intellispin feature was pulled from their green drive spec page and is listed with tler as to why NOT to use them in raid.
Click to expand...

But Intellispin isn't variable speed. Never was.
 
Engineer

Engineer

Elite Member
Oct 9, 1999
39,230
701
126
Gillbot said:
my mistake, I misread the spec page and made a silly assumption
Click to expand...

Nah, it's an easy thing to do and a great marketing ploy by WD. Did not mean to sound like an ass ole buddy, sorry. :oops:

By the way, I have two of the Hitachi 2TB Green drives in basically the same setup (except Raid 1). Get "Verify errors" from time to time...is this normal or something to do with the non TLER Green drives?
 
Cerb

Cerb

Elite Member
Aug 26, 2000
17,484
33
86
benzebut said:
Very good article thx,

so in conclusion my green drives without tler is the real problem.
Click to expand...
Well, green drives. Not having the ability to be told to stop sector recovery is a marketing decision from both sides, and affects speed because the array will be verifying and rebuilding itself, even if nothing is wrong (IE, if the controller/driver could be told to just wait on the drive, it would not be an issue for non-enterprise users). Drives that aren't part of a for-RAID series will have this problem.
 
F

FishAk

Senior member
Jun 13, 2010
987
0
0
It's really not a big deal for you at all. Simply switch four of the drives to RAID 10, (With a small portion of the array set to RAID 0 for stability) and use the other 2 disks in single drive mode for backup. You will have decent speed and reliability- even with the WD drives.
 
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