What should I do with two SSD's?

[Keith_W]

First post!

All right, this is the scenario. Please bear with me.

I have bought two Intel X-25M 160GB G2 SSD's. The original intention was to RAID 0 them, until I learnt that I will lose the TRIM function if I did this. I wondered what the consequences of losing TRIM would be, and this article by Anand answered the question very well. In particular, I saw that write performance on this drive drops from 38MB/s to 14MB/s with no TRIM use. I have also read elsewhere that RAID 0 on SSD's confer hardly any real world advantage, even though they bench very well.

In other words, if I RAID 0 the drives, I gain little if any performance, and stand to lose write performance because of loss of TRIM. This much I understand.

However, my problem is that I already have the damned drives. Two of them! My question is: what is the best way to utilize the second SSD?. I have thought of these options:

1. RAID 0 them anyway. Use the manual TRIM tool in Intel's SSD toolbox (as described by Anand here). I am not sure if this will work on a RAID 0 array?

2. Use first drive for boot, 2nd drive for programs. Reasoning is that it will keep more free space on each disk, which will improve write performance in the long term.

The rest of the system: Intel i7-960, EVGA X58 760 Classified, 6GB RAM, 2x 1TB Samsung HDD's, Radeon 5870, and Windows 7 Professional.

Thanks in advance for your help.

 

[Craig234]

That is funny - I came here thinking of posting a thread 'what should I do with two SSD's' since I have two Intel 80GB, and the same question, decided not to post the thread and you posted it

 

[zuffy]

I have an extra 80GB too. I will just hold on to until I get a new laptop or one of my SSD die.

 

[Hacp]

Put that extra one in your laptop.

 

[Yuriman]

I have two 80's and I put them in raid. Performance is performance, no matter how you look at it, and my un-trimmed writes are still as good or better than a single trimmed drive.

You cannot manually trim a raid array, the SSD toolbox will not allow it.

If you had two 80's, I would say raid them as much for the extra space as for the speed, but if -> I <- had two 160's, the second one would probably go in my laptop.

 

[Anubis]

i think you should give the 2nd one to Anubis

 

[Keith_W]

Thanks, but my laptop already has an SSD in it.

 

[jjmIII]

Simple: build another rig, or buy another lappy

 

[LOUISSSSS]

Pm me to sell!

 

[Yuriman]

If your laptop already has an SSD, I'd say raid them. Twice the space, twice the speed.

 

[lsv]

If your laptop already has an SSD, I'd say raid them. Twice the space, twice the speed.

 

[ss284]

One for OS, one for games.

 

[veri745]

One for OS, one for games.

+1

 

[Yuriman]

FACEPALM

Please, explain.


Useful link:

http://www.madshrimps.be/?action=getarticle&number=2&artpage=4417&articID=976

Sequential and threaded 4k read operations see a ~100&#37; speed increase, the ideal result when going from one to two disks setup. The single threaded random 4k drops about ~20% though. Read Access times go slightly up, but negligible.
-----------
Write performance is up all over the chart, the biggest gain is random 4k: 136% faster! Write access is also better with the drives in RAID.
-----------
The smaller the files, the bigger the performance increase, RAID + OS cache really pays off here, almost 3x faster than single disk!
-----------
Sequential read tests are quite promising, at its worst there&#8217;s a 153% performance boost; average read is 2x better than single disk.
-----------
The write performance boost is less pronounced in this test, hovering at ~60% average.
-----------
Random write is &#8220;better&#8221;, meaning there&#8217;s less loss of performance this time with smaller file chunks.
-----------
Overall we can conclude that you can expect a 50~200% boost in disk performance going from single SSD to two of them in RAID 0. Sequential operations will benefit the most, but smaller file operations won&#8217;t be slower than a single disk, on average.

 

[GoSharks]

Please, explain.


Useful link:

http://www.madshrimps.be/?action=getarticle&number=2&artpage=4417&articID=976

And I'll bet that none of that will actually be noticeable in a real-life situation...

 

[Swivelguy2]

Please tell me what process you went through to arrive at possessing an unexpected surplus of SSDs. I would like to have this "problem."

 

[Yuriman]

And I'll bet that none of that will actually be noticeable in a real-life situation...

Yeah, it's only twice to three times faster.


Point is, faster is faster. What is he going to do, toss the other in a drawer?

 

[Yuriman]

Also,

2. Use first drive for boot, 2nd drive for programs. Reasoning is that it will keep more free space on each disk, which will improve write performance in the long term.

Not sure how you figure that. You're still distributing the same amount of data across the drives, you're just not striping it.

 

[Keith_W]

Thanks everyone for your response. Yuriman you have gone a long way towards persuading me to install them as RAID 0. That article you linked to on Madshrimps was pretty helpful, although I am still not sure how much those synthetic benchmarks will translate to real world performance. In particular, I note that those Madshrimps benchmarks were done on a new pair of OCZ SSD's with garbage collection. The tests were not done on a "used" SSD where most of the cells had been written to. Perhaps the outcome of the test would be different if they had filled up the drives? With no TRIM, there is a possibility that the write performance may slow down to a crawl.

Swivelguy as I explained in the first post - I bought the drives planning to RAID 0 them. However what I subsequently learnt gave me second thoughts.

 

[skid00skid00]

I used my 2 gen 1's for OS, and swap files (incl. Photoshop).

 

[Yuriman]

Here's a good article showing TRIM vs no TRIM.

http://www.anandtech.com/storage/showdoc.aspx?i=3667&p=1


I'd say that overall, the performance increase from RAID outweighs the lack of TRIM (significantly).

 

[Keith_W]

All right, I have been back on forth on a couple of forums and I have been doing a lot of reading. Bottom line: I have decided to RAID 0 the SSD's with an LSI 9211-4i RAID card. These are the reasons:

- the write caching on the RAID card will significantly outweigh any potential loss of performance from lack of TRIM,
- TRIM sacrifices SSD longevity in return for better write performance in the long term,
- a RAID card's controller is significantly faster than the built in ICH10R controller on my motherboard,
- the outlay is modest - USD$200 or thereabouts. I am trying to source a card in Australia, but without much success so far. The final cost will depend on where I can get the card from.

Thank you all for your help.

 

[RaistlinZ]

Once developers start allowing TRIM on RAID 0 I think the world is going to explode, literally. 80GB x 2 will be the new "must have" setup. I look forward to it.

 

[taltamir]

1. RAID 0 them anyway. Use the manual TRIM tool in Intel's SSD toolbox (as described by Anand here). I am not sure if this will work on a RAID 0 array?

that will not work. whenever you delete a file windows 7 sends a trim command. it doesn't care if it is an SSD or a spindle drive, it sends it. Spindle drives ignore it as an unkown command, the raid controller in your mobo will drop it as an unknown command, SSD connected via AHCI receive it and apply it.
the ssdtoolbox will send TRIM for all the free space, but it will do you no good if you have a raid controller that is dropping he command.
Actually, there is an issue with intel's AHCI drivers that they also drop it, you have to use MS default drivers (install windows with BIOS set to AHCI, not IDE or RAID, and do NOT install the AHCI drivers from intel website, just leave it with what came with windows).

My suggestions on what to do, in order:
1. Sell it, put the money aside. In 6 months (Q3 this year) intel will come out with the G3 drives, less than half production cost (again), and increased speed (again)...
2. if your laptop doesn't have an SSD, put it in it.
3. use one for windows+programs, and the other fro games.

 

[Craig234]

Once developers start allowing TRIM on RAID 0 I think the world is going to explode, literally. 80GB x 2 will be the new "must have" setup. I look forward to it.

You should check the definition of the word literally.