# 1x 120GB SSD or 2x 60GB SSD in RAID?



## spirit (Sep 17, 2011)

Hi all. I am thinking about upgrading my main system in terms of boot drives, preferably looking to replace my 7200RPM WD 2TB HDD with an SSD. I'd like to have about 120GB storage space so I can install Windows 7 x64 and all my programs and have some room to spare (I'll store other stuff on my 2TB drive), but I have got a few questions to ask about SSDs though,

1. Should I get 1x 100GB or 120GB SSD or 2x 60GB SSD in RAID? Which option would be faster? Buying 1x 120GB SSD works out about £10-£20 cheaper than 2x 60GB drives in RAID, but if I put the 2x SSDs in RAID, would my system be faster? I've never really needed to use RAID before, so would putting 2 drives in RAID allow Windows to see both drives as one? A bit like the opposite of a partition? On Amazon right now there is a 96GB Kingston V+100 SSD for about £82, so would two of these in RAID equate to 192GB of total storage for about £164? Does RAID theoretically double the speed if you have two drives? I'm not even entirely sure if you can put SSDs in RAID, so some help here please on my buying choice?  

2. Which SSD(s) should I get? Been looking about on the internet and noticed that although the Kingston V+100 96GB does appear to good value for money for about £80 from Amazon, the read and write times are about half of what the OCZ Agility 3 can offer. However, I've done some research and found reviews on the internet about OCZ Agility 3 and Vertex 2 drives with people complaining that they fail after very mild use or (with the Agility 3 especially), people are getting BSODs. Once I had just built my PC, thanks to faulty RAM, I got the BSOD a lot so really I wouldn't welcome it's return. The other option is the Corsair Force 3 6GB/s 120GB SATA, and this offers fast read and write times (read 550MB/s, write 510MB/s) for good value (about £135).

So those are my two main questions, and any buying advice is always welcome. 

Thanks


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## TrainTrackHack (Sep 17, 2011)

> Does RAID theoretically double the speed if you have two drives?


SSD performance in RAID0 scales close to linearly with the number of drives... so as long as the individual 60GB drives are as fast as the single big drive, yes, you will have essentially double the performance.


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## spirit (Sep 17, 2011)

So using the 2x 60GB drives would be faster than the 1x 120GB drive then? So if one of the 60GB drives had a read speed of 525MB/s, with two of them I could potentially be getting 1050MB/s?


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## linkin (Sep 17, 2011)

SSD's tend to lose garbage collection and TRIM in RAID. RAID SSD's is also useless unless they are PCI-E as SATA3 will limit performance.


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## spirit (Sep 17, 2011)

OK thanks for the information. I am guessing you would recommend 1x 120GB SSD over 2x 60GB then? I am looking at the Force 3 120GB by Corsair at the moment, £134.99, so pretty good value I think? 

The Force 3 is capable of 6GB/s, however my motherboard (Foxconn H55M) can only do up to 3GB/s I think? So would I be getting the higher read and write times (up to 500MB/s on read and write) when I use the Force 3 with only a 3GB/s connection? 

Sorry about all these questions, hard drives/SSDs and storage aren't really my thing.  I'm more graphics cards and CPUs!  But as is the way with everything technology-based it seems as you get interested in buying one you learn more about it by doing research.


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## TrainTrackHack (Sep 18, 2011)

linkin said:


> RAID SSD's is also useless unless they are PCI-E as SATA3 will limit performance.


No.

I wouldn't think a RAID0 setup with only 2 SSDs would come even close to saturating a SATA3 link. I simply haven't heard of SSDs that have that kind of read/write speeds. Even in the unlikely event that this did happen, the bottleneck would be insignificant and the time such speeds could be sustained so short that there's no way it would matter at all.

EDIT:





> The Force 3 is capable of 6GB/s, however my motherboard (Foxconn H55M) can only do up to 3GB/s I think? So would I be getting the higher read and write times (up to 500MB/s on read and write) when I use the Force 3 with only a 3GB/s connection?


You're talking about SATA transfer speeds. Those are the theoretical maximum speeds of the connection, but in no way reflect the performance of the drive. Most good properly set up SSDs can reach read rates over 200MB/s AFAIK (still unable to saturate even your slower SATA connection), though I'm not too up to date with the performance of recent SSDs. The slower connection would bottleneck a RAID0 setup when doing really heavy reading, though. As long as you're only getting a single drive, you don't need to worry about being bottlenecked at all.


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## linkin (Sep 18, 2011)

Drives are now hitting 550-600MB/s. Theoretical SATA3 limit is 768MB/s (excluding overheads) so we are already getting close. Putting two fast SSD's into RAID wouldn't give you a whole lot of extra speed (certainly wouldn't double it, either.)

As for TRIM and Garbage collection in raid, I suppose I'm thinking about the first drives that came out.


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## TrainTrackHack (Sep 18, 2011)

> Drives are now hitting 550-600MB/s. Theoretical SATA3 limit is 768MB/s (excluding overheads) so we are already getting close. Putting two fast SSD's into RAID wouldn't give you a whole lot of extra speed (certainly wouldn't double it, either.)


Sustained speeds? If those are just burst rates, they don't mean that much but if those speeds can indeed can be sustained... damn, I'm ordering one.


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## linkin (Sep 18, 2011)

hackapelite said:


> Sustained speeds? If those are just burst rates, they don't mean that much but if those speeds can indeed can be sustained... damn, I'm ordering one.



Yeah, sustained speeds like all other SSD's


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## spirit (Sep 18, 2011)

Hello, sorry for the later reply, I was out for most of yesterday.

OK I think I'll go for 1x 120GB Corsair Force 3 then if RAID won't make my machine much faster.


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## porterjw (Sep 19, 2011)

linkin said:


> Yeah, sustained speeds like all other SSD's



That's just sick - seems I need to upgrade to one of those and lose another HDD


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