NAND Flash Faces Off - Synchronous vs. Asynchronous

News flash! All flash NAND is not created equal! Sure, you know about multi-level and single-level NAND when it comes to speed, but what about synchronous and asynchronous NAND inside your shiny new SSD? We have answers and tell you where your money is best spent for real data speed.



We’ve shown today that a synchronous flash drive will outperform its asynchronous counterpart by a substantial margin in all of our real world tests. In the synthetic tests we saw bits and pieces of the synchronous dominance but you really have to dive into the real world stuff to see how much performance is gained by spending a little more money for the superior product. Reviews that are using all synthetic and canned benchmarks to extol the performance of asynchronous NAND flash SSDs are simply misleading you.

The cost premium for synchronous drives is another area of misconception. Two days ago I read a preview article which stated there is a $100 price gap between the two classes of SandForce SF-2281 drives, but that isn’t the case as we can show you with current Corsair SSD deals we found. In the 120GB capacity size we find the asynchronous flash Corsair Force 3 costs $189 after a $10 MIR with Free Shipping at Newegg. (This price has dropped to $175 in the last two days.) The flagship Corsair Force GT with synchronous flash and much better real world performance is now down to just $234.99 with Free Shipping after using a HardOCP instant coupon code (HARDOCPX8X3E) at Newegg that is valid through next Tuesday. (This price has dropped to $223.49 in the last two days.) With the synchronous flash Corsair Force GT you get better performance out of the box. Better performance when the drive is half full and much better compressed data performance as our tests have shown. While many asynchronous SSD drives do not include a 3.5" desktop adapter bracket the synchronous Corsair Force GT unit does. With the current prices there really isn’t a reason to consider the slower drive in this capacity size. And you avoid the mail in rebate with the Force GT!

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Things do change a bit in the larger 240GB capacity arena. Here we see the asynchronous flash OCZ Technology Agility 3 priced at $424.99 with Free Shipping (down to $420 today) and the synchronous flash Vertex 3 at $498.99 with Free Shipping (the only price that has not fluctuated). A $80 Dollar price difference can make or break a purchase since it's a significant premium. Still the delta is less than $100.

Things get interesting here though for the enthusiast. You can achieve much better performance with two 120GB Corsair Force GT drives in RAID 0 using your P67 or Z68 chipset’s native SATA III RAID than you can with a single 240GB SSD. Obviously RAID 0 has some associated risks, but we are not going to argue those at the moment. Given the pricing shown above, you are up to roughly $450 with two drives giving you a 240GB capacity but nearly double your performance over a single drive since this class of SSD scales well in RAID. Two Corsair Force GT 120GB drives in RAID 0 on a native Intel SATA III chipset is the ultimate configuration for the power users at this time.

The Bottom Line

The first time we ran into a SandForce SF-2281 controlled SSD paired with asynchronous flash was while testing the OCZ Technology Agility 3 240GB. On the surface the drive performed well but when we started hitting it with real world tests it quickly became apparent that the Agility 3 wasn’t much faster than last year’s Vertex 2. We were not happy with the performance, but the Agility 3 was also $100 less at the time than the Vertex 3, so there was still solid value in the offering.

Things are different now. Faster synchronous product prices have dropped. While the synchronous prices are not at the level of asynchronous drives, the difference in price has gotten much smaller, certainly giving the faster synchronous drives a better overall value.

Another point in this conversation that must be considered is NAND flash pricing. NAND is a commodity like crude oil and prices change daily (As you can see from our price changes noted above that happened in a 48 hour period.), so we are not sure if this narrowing gap trend will continue but certainly we hope so. The SSD industry is still very immature and more competition is being seen every day. SSDs are still far from being a commodity as a unit itself, but that will happen much quicker than what we saw with the traditional spinning disk. The fact is that SSD drives are "easy" to manufacture compared to a spinning hard drive and sooner than later we will see a bevy of SDD drives being marketed bearing many brand names.

We highly suggest weighing the value of the better performing synchronous solid state drives using the SF-2281 SATA III controller. For a few dollars more, a synchronous SSD will likely deliver a much better enthusiast experience.