2 SSD Raid means 150mb write + 150mb write?

[PBanger]

If I buy 2:

Kingston SSDNow V Series SNV125-S2/30GB 2.5" 30GB SATA II Internal Solid State Drive (SSD)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820139162

and put these 2 SSDs in a raid. The 1st SSD in 0 and the second SSD in 1. This will be a striped raid. Once the raid is setup will I get a 300MB write speed, because the FIRST SSD has 150MB write speed and the SECOND SSD has 150MB write speed. Will my new striped raid have write speed of 300MB and read speed of 100MB, because the read speed is also doubled like the write speed.

If I explained it wrong can you tell me if it's possible to add write/read speeds when using 2 or more SSDs.

p.s I know the SSD I linked has 150MB write, instead as a math example I used 150MB because it's easier to add.

[SpoonXps]

Very interested to know also.

[Kasm]

The 1st SSD in 0 and the second SSD in 1. This will be a striped raid. Once the raid is setup will I get a 300MB write speed, because the FIRST SSD has 150MB write speed and the SECOND SSD has 150MB write speed. Will my new striped raid have write speed of 300MB and read speed of 100MB, because the read speed is also doubled like the write speed.

If I explained it wrong can you tell me if it's possible to add write/read speeds when using 2 or more SSDs.

p.s I know the SSD I linked has 150MB write, instead as a math example I used 150MB because it's easier to add.

I think you mis-understand Raid. You can't put the first SSD under Raid 0 and the second SSD under Raid 1. They will either both be Raid O (striped) or both be Raid 1 (mirrored).

To have both a Raid 0 AND Raid 1 on one computer you will need 4 SSDs, or intel matrix raid.

Anyways, if you use Raid 0 you will be double the write and read speed minus the associated overhead of the raid process. If you use Raid 1, then you will have the write speed of the slowest drive you use. Read speed depends on the raid controller, some read at the speed of the slowest, some read the data like a Raid 0.

[MattNo5ss]

Where did you get 300MS/s write and 100MB/s read? The SDD's specs list 180MB/s read and 80MB/s write. So, theoretically you will have 360MB/s read and 160MB/s write in a RAID0 config. But, as Kasm mentioned there is "overhead" which will reduce the speed a little from the theoretical values.

[Dukeman]

To calculate the impact of JBOD or Single drives' Bus saturation, OS mucking about, and Controller processing, overhead, take max transer rate of the slowest part (controller or drive) and multiply by 0.8.

For RAID multiply by .7 due to extra overhead of chunking up or multiplying the data between drives.

This will give you a reasonable target to shoot for.

i.e. 360MB/Sec theoritical Read speed would be in reality be 360 x 0.7 = 252MB/sec or in other words, still awesome! :)

[I.M.O.G.]

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[MattNo5ss]

To calculate the impact of JBOD or Single drives' Bus saturation, OS mucking about, and Controller processing, overhead, take max transer rate of the slowest part (controller or drive) and multiply by 0.8.

For RAID multiply by .7 due to extra overhead of chunking up or multiplying the data between drives.

This will give you a reasonable target to shoot for.

i.e. 360MB/Sec theoritical Read speed would be in reality be 360 x 0.7 = 252MB/sec or in other words, still awesome! :)

That's interesting. Where did you get that "rule of thumb" ?

[I.M.O.G.]

I wondered the same thing, but it looks to be generally pretty accurate as a loose estimate from the results I've seen.

[MattNo5ss]

I guess if you looked at a lot of RAID benches you could just avg the results and divide it by the theoretical speeds to get an avg scaling factor.

[Headstand]

With the 0 and 1, I think he meant SATA ports. As for raid, and doubling the speeds, I got almost a perfect double with my OCZ Agility's. Check it out HERE (http://www.overclockers.com/forums/showthread.php?t=635250).

[Evilsizer]

To calculate the impact of JBOD or Single drives' Bus saturation, OS mucking about, and Controller processing, overhead, take max transer rate of the slowest part (controller or drive) and multiply by 0.8.

For RAID multiply by .7 due to extra overhead of chunking up or multiplying the data between drives.

This will give you a reasonable target to shoot for.

i.e. 360MB/Sec theoritical Read speed would be in reality be 360 x 0.7 = 252MB/sec or in other words, still awesome! :)

That's interesting. Where did you get that "rule of thumb" ?

I wondered the same thing, but it looks to be generally pretty accurate as a loose estimate from the results I've seen.

my write results for a raid-0 setup on agility drives is a fluke? the read results support i guess in a way what he said but not that low. 230x2=460MB/s, max im seeing is according to atto is 448MB/s. write speeds are way higher then 135x2=270MB/s, with atto showing 329.8MB/s. looking at the crysaldisk mark numbers though, that seems to support what he says but only when looking at the 512k,4k results.

[tachi1247]

Like mechanical disks, SSD drives scale pretty linearly so adding more drives should continue to multiply the performance you see up to a point. For most of us, it doesn't make sense to put more than 2 SSD in RAID.

[Evilsizer]

well i just noticed the specs on that drive...

Sequential Access - Read up to 180MB/s
Sequential Access - Write up to 50MB/s

reminds me of the OCZ 30gig Solid drive i have sitting on my desk. has about the same specs listed. the OP does have his numbers off a bit, he could see around RW 340-350MB/s read and 80-90MB/s write. i am betting they are based on a jmicron controller like the Solid has. it does have some kind of tweaks to the FW to stop stuttering so i have read on the jmicron+kingston drives.

i would still highly suggest skipping that drive and looking at one with a touch higher cost. that will have a much better controller and offer higher read/writes speeds.

[PBanger]

COOL.

Thanks everyone, my question definitely got answered.

[deathman20]

I thought the V series is based off Intel's own V series drives. Though these do have a smaller size though maybe it isn't an Intel spec drive.

Reads and writes vary though depending on controller. Max sure but it could dip down far lower or even higher then speced depending on the controller.

[Evilsizer]

I thought the V series is based off Intel's own V series drives. Though these do have a smaller size though maybe it isn't an Intel spec drive.

Reads and writes vary though depending on controller. Max sure but it could dip down far lower or even higher then speced depending on the controller.

they still have the older jmicron base V series on newegg :( i think it was the V+ line your thinking about which has ssd's from intel. it is easy to spot the non-intel drives from there size. intel goes in 40gig,80gig,160gig, non-intels 30gig/32gig, 60gig/64gig, 100gig/120gig/124gig, 200gig/250gig/256gig, 500gig/512gig, 1TB.