Advice on SSD Raid-0 Setup

[AQFT]

Hello,

I am thinking of setting up a raid-0 array using a Samsung 830 512GB drive with a Samsung 840 EVO 1TB drive on an Asus X79 Sabretooth board.

1. Is it a good idea to mix these two drives together?
2. Will I get a significant speed boost?
3. What is the best way to raid them together before I install Win 7 64 bit on them?

I will be backing up the raid-0 to another drive.

Thank you for your time.

 

[velis]

?????
You are planning to RAID-0 two drives of different sizes? You do realise that total array size will be 1TB, right?

1. I don't think this is a good idea
2. Not in real life usage. Unless you really need 500MB+ / s transfers, you will see no improvement whatsoever. Either of these SSDs feeds data fast enough that any app startup depends more on the CPU than on the disk. I doubt even databases would benefit this setup much since IO/s will not go up with RAID.
3. In BIOS

 

[OlyAR15]

Very bad idea. Unless you spend your time running benchmarks, it is unlikely you will notice much of a difference. And you will lose about half a gig of storage space,which is a significant hit considering the price of SSDs compared to mechanical drives, and increase the risk of data loss.

Still, it's your money.

 

[Berryracer]

RAID on SSDs is pointless, gives you less 4K speeds which are the most important for OS snapiness, longer boot time due to the initialization of the RAID Controller on startup, and higher risk of data loss!

http://www.overclock.net/t/1500862/1-single-ssd-vs-2-ssd-raid-0

If you have a workload in which you need high sequential speeds, then in that case you are good to go with a RAID 0 array. Otherwise, RAID 0 with SSDs is pointless besides having a bit more e-peen. The numbers don't lie, but they can be deceiving...remember, these are synthetics tests, not real world workloads. Just because you see 1GB/s bandwidth capability, it doesn't mean you necessarily will take advantage of it in actual use. You are right, "right choice is the one the individual decides is best for his/her application." However, many have little knowledge on the matter and can not make make an educated decisions. Thus, they have to turn to those with knowledge on the subject for educated advise. Otherwise, you end up losing time and money over uneducated decisions.

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I've used Samsung 850 PROs in RAID 0 mode, believe me there is 0 difference between RAID 0 and a single SSD when it comes to the performance that a normal user would experience because RAID 0 mode doesn't improve on the 4K random reads/writes which is what a normal or even power user would use most of the time, it only helps in sequential reads/writes, say for instance if all you do is copy large video or data files (10GB ++) all the time from one partition to the other which I doubt that you do....

RAID 0 mode is great to show off high benchmarks, but for a normal user, it only increases the risk of failure, higher latency, longer boot times due to the 2 - 3 seconds required for the RAID controller at startup, just not worth it, get the largest single SSD that you can afford and be done with it

Excerpts from the Samsung SSD Whitepaper

"... Fast sequential speeds allow for quick file copies and smoother performance when working with large files, like videos. However, it is random performance, measured in Input/Output Operations Per Second (IOPS) that is, perhaps, the most important performance metric for SSDs.

A large portion of storage activity is made up of 4K random writes, a metric that measures how well a drive will perform when writing small chunks of random data (e.g. changing a small piece of a Word or text file and then saving the changes). Users spend a majority of their time not copying large files or installing applications, but multitasking (e.g. email, web-surfing, listening to music, etc.) and working with various work and media files - tasks influenced by IOPS. An SSD can offer up to a 200x improvement in IOPS over a traditional HDD (results may vary based on HDD model).

For this reason, Samsung put a heavy focus on random performance when designing its SSD lineup, offering users industry leading Random Performance of up to 100,000 IOPS. This is performance for the real world; performance you will notice and appreciate every day ..."



"... most consumer workloads will be similar to 4KB data at QD 1 ..."



"... While the majority of client PC workloads will not exceed a QD of 1, some usage scenarios may generate a QD of 2-6 or even up to 10 (in limited applications). Data center applications, on the other hand, may generate massive numbers of Input/Output (I/O) requests, creating a QD of 32, 64, or even 128 in some cases (depending on the number of access requests per second) ..."



"... For the vast majority of users, the most meaningful Iometer scores will be those of 4K random Read and Write performance at a Queue Depth of 1-32 ..."



"... The most common queue depths to test are a Queue Depth of 1, which is typical of light consumer workloads, and a Queue Depth of 32, which is representative of a heavy workload as might be seen on a on a server (e.g. web server, database server, etc.) ..."



"... peak speeds are not a good indication of everyday performance. Users are typically not installing applications or copying massive files on a regular basis. Many manufacturers like to brag about peak performance ..."

 

[Murloc]

840 EVO is having issues and if you put it in a RAID you won't be able to use the "fix".

Leaving alone the fact that they are two different sizes and the reward is just not worth the complications and risks if you're a normal user.