OCZ Vertex v. SAS 15k RPM Raid 5
Question: How does a OCZ Vertex 120GB compare to an 8 drive 15k RPM 2.5″ SAS Raid 5 array with a fast Adaptec 5805 controller?
Answer: It is slower… kind of… but both options have some great features!
So at this point, what can a lone Indilinx based OCZ Vertex do?
As one can tell, the OCZ Vertex gets handily destroyed in read/write performance versus the 15k SAS drives. It should be noted that the Seagate Savvios are the 15k.1 generation, and not the newest. With that said, it is hard to argue with those numbers.
Those numbers don’t tell the entire story though. SSD’s are known for their ultra fast access/seek times. This is prominent, for desktop users, during startup. Loading Windows 7 on the Savvio array, with no additional disk access, took 33 seconds. The same task took 29 seconds on the OCZ Vertex. Frankly, there was not that much of a difference. The Savvios have quick access times for platter drives, and the throughput is quite crazy.
Where one does notice the difference is in the total boot times. SAS drives in RAID are going to require a controller to boot. The Adaptec 5805 has to go through a boot process, then initialize the drives, before Windows 7 loads. The Vertex runs off of the Intel ICH10R and thus goes directly from POST to OS boot. This makes a very pronounced difference if one needs to boot into a motherboard BIOS for example and change a value. Each time the PC is rebooted, and before entering the BIOS screen, one needs to wait for the RAID card bios to load.
There are other advantages to the single OCZ Vertex versus the SAS array and these advantages are related. In testing using trusty Kill-a-watt monitors the OCZ Vertex was using a maximum of 7.8w of power. The Vertex made no noise, and generated little heat. On the other hand, the SAS array had 8 drives spinning at 15,000 rpm. This causes lots of noise, lots of vibration, and lots of heat! Further, using 4-in-1 backplanes added additional fans to cool the drives. These fans also generated noise and vibration. The Adaptec 5805 took up a PCIe slot, and generates a lot of heat itself. The total Raid 5 SAS setup used 59w at idle, and 92w running disk benchmarks!
Hardware costs are fairly similar between the 250GB vertex (about $725 these days) and the 256GB SAS array (36.7GB * (8 drives – 1 parity drive)) which all-in cost $700. The SAS array does have the advantage of having the ability to sustain a drive failure, however has 8x the chance to have a drive fail as a single drive so this is necessary.
Overall, SSD’s are going to overtake SAS drives. For now, high-end SAS arrays offer great performance, and at a competitive price. With SATA-3 and next generation SSD’s, there is little doubt that SSD’s are going to render arrays like the SAS array here less desirable, but that is still a future looking statement. Video editing with 700MB/s reads is amazing!