# Transfer speed of RAID 0 (2+0)



## Pap1er (Jul 13, 2010)

Hello pals, i have one thing i want you to look at.
I have 2 raid 0 (2+0) configurations in my PC, 2x seagate 320GB and 2x seagate 500GB disks.
Few days ago i realize one thing that i cant understand. I was copying my home videos from one raid to another and meanwhile i opened web browser google chrome to check my e-mails and so on. Than i realized that transfer speed increased almost by 50% !! I was quite excited so ive made few benchmarks to confirm that. 

Here are screens of benchmark with and without google chrome opened:

without chrome






with chrome






This is something i have never seen before and this "feature" affects also USB drives and LAN transfer speed only with google chrome opened. Is that any driver feature that google chrome uses or just windows error? Im using hardware raid.

Here are my PC components:
Mainboard:	Sapphire PI-AM2RS780G
RAM:  4x2GB Kingston HyperX DDR2 1066MHz
CPU: AMD Phenom II X4 Black Edition 965, 3700 MHz (18.5 x 200)
VGA: Sapphire HD5770 1024MB
OS: Windows 7 x64 Ultimate

Could you please tell me your opinion ?


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## slyfox2151 (Jul 13, 2010)

..(your screen shots arnt showing up) maybe use the techpowerup image host? www.techpowerup.org

could just be a bug



update your drivers for the raid and see if that fixs it.




what hardware raid controller are you using?


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## Pap1er (Jul 13, 2010)

*Raid*

Im using "Embedded AMD SB700 Southbridge Chipset Supports 6 x Serial ATA2 HDDs with RAID 0, 1 , 10 Functions"

Ill take a look on new drivers and post back


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## slyfox2151 (Jul 13, 2010)

thats still software raid  


not sure why your scoreing higher with chrome open... must be a driver error?


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## Pap1er (Jul 13, 2010)

*raid 0*

New chipset and raid drivers has made no changes at all.


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## lism (Jul 13, 2010)

The problem with openening applications is the chunks of data are smaller on both drives and therefore the seektimes will be larger. If your moving a huge amount of data from one set to another set while opening any type of application it will cause problems like this.

Raid is fun esp with huge data transfers but fails at doing multitasking as a diskset.

Plain simple. Just run one application at a time to have the maximum throughoutput.


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## Pap1er (Jul 13, 2010)

*raid 0*

But 50% boost in throughoutput when i open google chrome? little strange, isnt it?
And now i dont think its raid problem at all, because it affect also data throughoutput from USB drives and throughoutput of LAN... stranger and stranger


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## AsRock (Jul 13, 2010)

Get a large file and time it for using chrome and not using it and see for sure if it's faster..  That way you know if it's a bug or not


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## Pap1er (Jul 13, 2010)

Its definitelly faster with chrome opened, im sure...i could not belive witout any tests. I tried to copy DVD iso from one raid to another, i tried copy 1GB video file from USB key and finally i tried copy DVD iso from my media tank popcorn A-200 via LAN and in all cases transfer speed raised after opening chrome. sick i know...


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## Pap1er (Jul 13, 2010)

*solution...*

Seems like southbridge SB700 is responsible for this kind of "mystery" boosts and slowdowns.
I read somewhere that thers problem with load balancing in SB700 and this problem persist here since SB600...  many users reports problems after enabling AHCI mode or applying NCQ in raid with SB600 ~ SB700. Its true that i have played with NCQ some time ago, but i did not found any performance advantage. This seem to be conclusion of my playing 
I did not find any real solution for this problem. I found just partial solution, thers some driver which can remove this problem of innacurate load balancing but in cost of heavy CPU utilization (about 30%) what is not acceptable in my opinion.


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## Wastedslayer (Jul 13, 2010)

Link to this partial solution


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## Pap1er (Jul 13, 2010)

I found some information about this problem on this page of AMD game forum:


> http://forums.amd.com/game/messageview.cfm?catid=261&threadid=115133


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## cadaveca (Jul 13, 2010)

Seems AMD is using web-server data management software for RAID control(IE=based), and replacing IE with Chrome gives speed boost?


Did I get that right?


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## Pap1er (Jul 14, 2010)

cadaveca said:


> Seems AMD is using web-server data management software for RAID control(IE=based), and replacing IE with Chrome gives speed boost?
> 
> 
> Did I get that right?



Nah just opening chrome itself gief boost, but its because bugy southbridge or southbridge drvers... i dont know


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## cadaveca (Jul 14, 2010)

Yes, I know, however, it strikes me as odd that you use web browser to access the AMD "RAID Console". i think this is why you have noticed this "bug".


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## ISSA2000 (Jul 16, 2010)

known bug with the amd contller (raid version), try latest bios+ drivers..seams to fix it..
(multi file acces using raid)(or slowdown with few access)


this has been reported by many other people on many diff web sites


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## Pap1er (Jul 17, 2010)

ISSA2000 said:


> known bug with the amd contller (raid version), try latest bios+ drivers..seams to fix it..
> (multi file acces using raid)(or slowdown with few access)
> 
> 
> this has been reported by many other people on many diff web sites



Unfortunatelly I have flashed latest available BIOS for my motherboard and installed latest drivers, but problem still persist.


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## adrianx (Jul 23, 2010)

So this is strange
intel array is on intel SASUC8I (aka LSI) on pci-x X8 with 4x 500GB seagate with 32MB cache/hdd

amd array is on internal AMD 890FX chipset with 2x 500GB seageate with 16MB cache/hdd

the windows 7 ultimate have 7 day old, and it's with all updates are up to day.

the old sistem with 790fx chipset have better performance on intel raid controler



frist with out chrome started

the second is with chrome started


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## mastrdrver (Jul 23, 2010)

It could also be a problem with the Gigabyte board.

On my 790fxt-ud5p when I had a raid 0 setup it will kill my memory performance in other applications just using it everyday like.


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