phillhutt

Recently I have seen a couple of posts about solid state drives.

The first one, here, is about intel testing a 4-terabyte solid state drive array. 4TB. Pretty cool. I think the main reason why it is a big deal is because they are going to be really really fast and use a lot less power. Another good reason why SSD could be really good for commercial use is that it is fairly predictable. They know that the drives will not last forever (especially if they are being used 24/7/365) but neither do current HDDs. However, you can never really be sure when a HDD will fail. SSD drives have more of a definite life span, they have a certain number of expected read/writes before they start to fail. This could mean a lot more pre-empting disk failures, meaning less downtime? It is always good to be able to predict things. Good for budgets too.

Currently as per this article it seems that Intel is currently offering a 3.8TB SSD rack consisting of 120 drives. Thats a lot of drives. If you compare with a 120 drive rack of HDDs (8.8TB) you use 5 times less power and get 115 times faster (apparently) IOPS (in out operations per second). So, it seems like half the storage space for much more performance and lot less power. As for price, I don’t want to know what 120 ~3GB SSDs would cost. If you were really interested in performance I guess it would be worth it. Have a look at the second article at least, there is a nice graphic with the differences between the HDD rack and the SSD rack.

As for the new 4TB SSD array I’m not sure how many drives that is supposed to consist of.

Ok, I just had a read of the Fusion io website where the SSDs for the speedy 4TB rack come from. I had a look at one of the drives they have. They have an FAQ with more details on my previous statement about limited read/writes to a flash drive.

Doesn’t NAND flash have a write limit? How does that effect the lifetime of the ioDrive™ ?
NAND flash has a limit on the number of writes that can be done to an individual cell. The particular limit
depends on the type of flash used. For Single Level Cell (SLC) NAND, the limit exceeds 100,000 writes to a
cell, whereas for Multi Level Cell (MLC) NAND, it is on the order of 10,000 writes. Hence, in order to exceed
the limit of a single 80GB ioDrive™, you would have to write almost 80PB (Petabytes) of data. Streaming data
at 800MB/s to the card, it would take you 3.4 years of writing data non-stop to exceed the SLC limit.

So there you go, not too bad really. With heavy use you should get a few years out of it. I wonder what their unexpected fail rate is. That was actually the next question. Apparently since it doesn’t have any moving parts major types of failure (e.g. total disk failure) are extremely rare. Also, it is possible for individual chips to fail, but it automatically writes to the next adjacent chip with no data loss and only a slight reduction in overall storage capacity.

The other cool thing (maybe) is that it runs from a PCIE 4x slot. It acts just like another hard drive to the OS. So, I imagine if I had some money I could get one of these drives and push it straight into my desktop PC. It looks like they have 80, 160 and 320 GB “configurations” available.

Well thats enough for today.