SPCR

Hi guys

I just wanted to enquire which memory would be best for my next build (still a looooong time off), as I'm a little uncertain at the moment. I'm planning on buying from the Kingston HyperX range, and the mobo I'm presently looking at will acommodate DDR3 1333 and 1600. The 1333 has a latency of 7 and the 1600 a latency of 9. Is there going to be a huge difference between the two? I'd always thought that lower latency was better, but I'll readily admit that I don't know a whole lot about memory.

http://www.ebuyer.com/product/169488
http://www.ebuyer.com/product/169240

And a quick second question. What's with the high cost of memory these days? Is it just the economy or is there some other reason for it?

honestly I dont know a whole lot about DDR3 ram, but basically, that latency time does affect performance. 1333/7 = 190 and 1600/9 = 177. If I were a betting man, I would say the 1333 would perform better? That is, if it can hold up to it's advertised latency times. I could be wrong..can someone with more knowledge on this confirm that?

Secondly the "high cost" you are referring to is DDR3 prices. Since it is relatively new to the desktop market, it's naturally going to be more expensive than the older DDR2 sticks. But, this is nothing new. I think my first laptop was 2 grand, and it probably had 1/100th of the power of my computer now ($800). Give it time, and you will see prices go down garenteed. I'm waiting about 6 more months to be the proud owner of a much much cheaper SSD.

Lower latency is better, but the actual latency is not just the number shown in the specs, but that number multiplied by the cycle time (the inverse of the clock frequency).

So, the latency for the DDR3 1333 CL7 is: (1 / 1333MHz) * 7 = 5.25ns

The latency for the DDR3 1600 CL9 is: (1 / 1600MHz) * 9 = 5.63ns

So there isn't actually much difference in latency. The higher clocked stuff will therefore likely perform better. However, improving memory performance makes only a very small difference overall, so I don't think it's worth buying expensive RAM.

Memory prices have always been all over the place, for a variety of reasons. If I had to guess, I would say that the reason for the current rise is Win7 (I bet memory manufacturers love Microsoft bloat).

Mr Evil > Inverting the terms doesn't change the situation. The 1333 set is better by the same margin as by RoGue's calculation. In your case, you're citing latency where lower is better, and RoGue's result in an "effective clock speed" where higher is better. As long as all the other latency parameters are more or less at a 7:9 ratio as the CAS, the 1333 kit is better.

I'm not too sure if the comment about the prices are the recent (ie: last 2 months) "boom" or higher cost of DDR3 in general, but I'm pretty sure it's the former. I have no idea why, I'm guessing it's xmas season price-gouging where they double the cost and then give you 30% off during boxing week or some other BS. I haven't seen them go back down yet, though... ditto with the Indilinx SSDs. It's pretty bad- see for yourselves with a random example of a RAM kit here in Canada:
http://hardwarecanucks.pricecanada.com/ ... e-history/

hybrid2d4x4 wrote:Mr Evil > Inverting the terms doesn't change the situation. The 1333 set is better by the same margin as by RoGue's calculation. In your case, you're citing latency where lower is better, and RoGue's result in an "effective clock speed" where higher is better. As long as all the other latency parameters are more or less at a 7:9 ratio as the CAS, the 1333 kit is better...

The difference is small. It's going to make very little difference in performance, and that difference will be swamped by the improvement from increased clock speed.

Yeah, I think ultimately Mr. Evil is right in that it will make VERY little difference between the two speeds. And in that case, I would get the 1333 to save money.

When building computers, always try to get the highest performance/cost ratio...you wanna spend money on bottlenecks. Save a little money on ram that might perform marginally worse, and put it towards an SSD. You will have a much much snappier system. (this is just an example, not what I recommend necessarily).

Thanks guys. 1333 it is