OCZ RevoDrive 80GB PCIe
Nice hardware but sadly quite slow by modern standards: 75 000 IOPS. Modern SSD can achieve similar performance. [Edit: as mentioned later on, the figures SSD manufacturers provide are misleading so the question remains: can this device provide constant 75 000 IOPS in which case it is much much better at that]
But it gave me an idea.
This one can house two SSD. It would leave me two on-board SATA completely free and server could still have SSD.
That would be the absolute best solution. It would mean I can have two Western Digital Re 3TB with two SSD which would give me double the IOPS vs. one and hence extreme performance on my pool.
While doing research on what would be the best SSD IOPS-wise, I found out the manufacturers exaggerate their IOPS figures. According to this the figures they give can only be achieved on a new drive for very short periords of time.
Some manufacturers seem to provide Sustained figures which use some sort of standard-type agreed-upon way of measuring the real IOPS figures, while others don’t.
OCZ gladly gives these figures for their Vector 150 drives but sadly 12 000 steady random writes isn’t that good at all.
And while this is quite an entry-level SSD and there are better it is of little use until they start to provide these measurement figures.
And one cannot trust the tests done by testers unless they understand this and run their tests for extended periors of time! Because otherwise we may get skewed results.
But the best plan still would be to get as much RAM as possible, then of course get as much disk as possible, and finally have fast FLASH storage for anything that spills over the RAM.
And with ZFS and FLASH cache I could perhaps even use consumer grade SATA to save money and still have reliability and performance.
Let us calculate for the fun of it.
Western Digital Red 3 TB, 2 pieces for 250 €
Sonnet Tempo SSD Pro, 250 € delivered
And it seems by comparing OCZ Vertex 460 120GB and OCZ Vector 150 120GB that they use similar technology on both of these since steady-state random write figures are exactly the same.
Looking at other parameters we go with the Vector 150.
OCZ Vector 150 240GB, 150 €
Which would give 6TB of storage with 240GB of L2ARC for 650 €.
Compared to original plan which was to buy 3TB enterprise quality SATA and combine it with 250GB SSD which would cost 180 € for Re4 3TB and 107 € for Samsung 840 EVO 250GB for a total of 287 €.
Now that’s a difference!
Good, bad? That certainly is a very good question. But the 650 euro one would perhaps provide much greater performance.
2.3 times the price for 2.0 times the capacity. The 0.3 should then be covered by the fact that there would then be empty slot for another SSD and by the performance increase.
So I think the 650 euro deal is the better one.
And with 4TB WD Desktop Mainstream one would get 8TB of storage for an additional 100 euro.
So 750 euros for 8TB pool with 240GB cache. That’s a shitload of money.
But still, that is only 9,3 euro cents a gigabyte of high-performance and reliable storage. 9,3 cents for gigabyte 10 years ago was considered cheap, and it was for hard drive only.
Raw enterprise storage would with Re4 3TB be 6 cents. So there is definite margin there.
But comparing these (raw vs. real setup) is quite useless. One can buy storage and that’s it but one can’t then just get the performance out of it.
Upgrade the disks to 5TB, add in another 240GB cache for a total of 480GB (or even 1TB) and you have 10TB pool with 1TB cache.
What would that cost?
WD Red 5TB, 2 pieces for 410 €
OCZ Vector 150 480GB, 2 pieces for 530 €
Sonnet Tempo SSD Pro, 250 € delivered
That would be 1190 € for 10TB high-performance, high-reliability storage pool.
Talking about enterprise or business money that is peanuts and nothing.
Edit: I made a mistake where I sacrificed reliability for money saving since I figured I won’t need faster disks because I have SSD to cache. But I still need reliable disks to achieve that reliability.
So the prices will go up by perhaps 20% since reliability still requires Re4 enterprise level disks for raw storage. Bonus from this accident is increase in performance.
So, now we would have 8TB pool with 1TB cache for 480 € for 2 pieces of Re4 4TB, 530 € for 2 pieces of OCZ Vector 150 480 GB and 250 € for Sonnet Tempo SSD Pro for a total of 1260 €.
Which of course is some 70 euros more for 2 TB less and for 20% larger MTBF, the performance increase and two years longer warranty time.
Seems to also have an order of magnitude lower rate of Non-recoverable read errors so go figure.
Disks for surveillance use I would never touch because those are made for video stream which isn’t too sensitive about bit flipping and other errors which can in the context of video be considered minor errors.