stupid question about raiding SSD's

mythrandyr · 27 Feb 2009 at 06:45

hi guys,

ok so i bought an SSD tonight and i'm looking forward to getting it and putting it through its paces but what i want to know is this:

can two 64GB hdd's from different manufacturers be raided together?

Because what i am thinking of doing at the end of next month is obtaining either a crucial or OCZ Vertex drive. So when raided i understand that i would get a single 120GB hard disk drive due to the Vertex being the smallest of the two drives but with the performance levels of either drive being different, would that have any kind of an impact on a raid between two different manufactrers SSD's?

For example would i maintain the Samsungs overall system performance and then some because of the performance of the Vertex in certain areas or would it make no difference at all? or am i being slightly more noobish than the average noob for asking?

cheers,

Myth.

linktoinsanity · 27 Feb 2009 at 09:41

Possible that they can be, but I'd stick two from the same manufacturer and the same size (infact then same model) together to be on the safe side. That's what I would do with mechanical hard disks aswell.

PistolPete · 27 Feb 2009 at 17:57

There is an arguement against the same make / model drive in RAID in that a batch might be dodgy, and having multiple drives from potentially the same batch could spell disaster.

However, in this day and age of quality control it's less likely.

mythrandyr · 28 Feb 2009 at 11:46

so you're suggesting, if i understand this right since i am quite tired at the minute, that 2 samsung drives, specifically from the same batch in raid, could be a bad thing? Has anyone actually raided two different makes of SSD together and posted a review or comment about their success with doing so because i would like to see the resulsts. The reason i'm asking is because i am not sure wether to buy a crucail 64GB SSD next month or to keep with Samsung. I don't see the need to stick to samsung if i could potentially get more performace in other areas using a sammy in conjunction with a crucial, otherwise if all it's going to do is create a single 128GB hdd, i don't see the point and will just stick with 2 sammys.

CaseyChaos · 28 Feb 2009 at 14:24

surely it depends on the raid you're using, if you're wanting the mirror raid then yes the same batch could cause you're backup 2 fail so not much point, if you're wanting to stripe then it don't matter because if one or both fail cos you lose all your data both ways.

If you can try find out if you could buy the same make and model but 2 different batches

Paul11 · 28 Feb 2009 at 14:36

i was say that two from the same batch makes more sense.

Worrying about a bad batch is just not relevant, imo, because you would send them back under warranty

i have two samsung SSD in RAID0. and love it.

i dont know the technicalities of having two different drives with different performance . maybe someone else can comment on that

CaseyChaos · 28 Feb 2009 at 14:48

yeah it's easy enough to send them back but what about all the data lost, some people have important files they don't want to lose and that's why they turn to raid for back-up

Paul11 · 28 Feb 2009 at 14:53

CaseyChaos said:
yeah it's easy enough to send them back but what about all the data lost, some people have important files they don't want to lose and that's why they turn to raid for back-up

well OP talks about performance, so i guess he means raid0 not raid1

and everyone should have backups . these days there is no excuse to blame anything for losing your data ...

if he just wants a raid1 for back up then i dont think it matters what drives you use.

and even then, i personally, would still make backups anyway.

Velineon · 1 Mar 2009 at 08:53

Sorry if im going off topic here, but is there really any difference in running SSD's in raid then having them in a single config? I mean if the seek time is instant on just one SSD, how would raiding improve them?

The Halk · 1 Mar 2009 at 12:05

It would improve the data transfer rate for transactions larger than the stripe size.

If you're going to RAID them then go for the same make/model/firmware. When you mix and match you'll get the lowest performance. SSDs don't perform the same across the board, a drive that might be faster than another drive may be slower with some file sizes.

DaveF · 1 Mar 2009 at 12:05

Velineon said:
Sorry if im going off topic here, but is there really any difference in running SSD's in raid then having them in a single config? I mean if the seek time is instant on just one SSD, how would raiding improve them?

You don't raid SSD's to get better seek time, you raid them for better transfer rates.

This is also true for HD's. Putting 2 HD's in RAID 0 can actually make latency worse. (Because you don't get the data until both drives have done a seek to the right location).

mythrandyr · 1 Mar 2009 at 12:55

right now i understand. The seek time of an SSD is what 0.1ms so no matter how many SSD's you raid together its always going to be the same, where as if you raided 10 magnetic drives together you still would not be able to get a higher seek time than 1 SSD.

And the raid configuration goes off the lowest values rather than the highest so that if i raided say an intel ssd with a vertex ssd then the system would underperform because it would be using the vertex ssd's performace rates which is why it's better to raid two of the same ssd's, which i think, if i understand correctly, provides a stable performance platform since they opperate on the same level.

you'll have to forgive my terminology since i am new to the SSD scene and don't understand the technology fully at the minute, it seems a pretty worthless venture now but i thought that it was a question worth asking.

The Halk · 1 Mar 2009 at 13:02

If you raided 10 mechanical drives you would not be able to get a higher seek time than 1 mechanical drive, in fact it would be worse.

The Vertex and the Intel drives are different. It is not the case that the Intel is better than the Vertex across the board, the Vertex is better than the Intel in some areas. It's not even clear which is the better drive overall. However putting a Vertex and an Intel in RAID would see performance worse than two Vertex in RAID or two Intel in RAID, since you get the worst of both worlds.