RAM Timings for Productivity

[thephatp]

I always see information on timings related to gaming, but never really on productivity (for me, web design/development, app programming).

I'm upgrading my system to a Q9550, and I'm trying to decide on the following:

8GB Crucial Ballistix DDR2 800 ($40 TOTAL if Frys gets more stock in time)
4GB Corsair DDR3 1333 ($70 AR, might be able to get 8GB, but it's more than I wanted to spend right now, but if the timings don't matter much, I may bite the bullet.)


How much do the timings play into non-gaming functions?

 

[GhislainG]

They're more important for benchmarks than anything else, but tighter timings are preferred as long as the system is stable. If you buy DDR2 modules rated at 4-4-4-12, then they should work fine (unless you buy some crappy motherboard). You can't compare DDR3 directly with DDR2.

Are you buying RAM and then a motherboard that will be compatible with it?

 

[thephatp]

Not necessary. Basically, I was trying to decide if I should upgrade my mobo at the same time as the processor & the RAM, since I want to do both. (I need to upgrade the RAM, and I really want to upgrade the processor.)


I was just thinking that if I'm going to buy 8GB of RAM now, does it make sense to spend money on the slower RAM (PC-6400), or would it be better to buy PC-10666. Then, when I started looking at the PC-10666, I noticed that the timings were much higher, and I'm not sure how that relates.

 

[GhislainG]

The higher the frequency, the looser the timings have to be. PC10666 runs at 1333Mhz, therefore the latency has to be higher than memory that runs at 800Mhz. Shouldn't you decide what CPU you want? If you buy an i7, then you also want triple channel DDR3 (3 modules). For a Core 2 or Quad, DDR2 is almost as fast and less expensive.

http://ixbtlabs.com/articles3/cpu/ddr2-800-vs-ddr3-1333.html

You can find other tests and they all reach a similar conclusion.

 

[jfurterer]

I'm trying to find the answer to this very question with a similar build. I work in web development and flash development using allot of photoshop, premier and 3d studio max. As far as timings are concerned I don't believe this will effect the performance of these apps by anything noticeable. Rather I find simply have MORE available ram is most important.

However the Q9550 runs at a core clock speed that is the same as the Q8200 that I'm looking to purchase, that is 333mhz. This number is important from what I've discovered about how ram behaves in systems prior to Core i7 and X85 chip sets where the memory controller is integrated with the i7 CPU. From what I've gathered your RAM will clock down to slower FSB. In our case our actual FSB is 333mhz (1333mhz effective). Therefore without over clocking DDR2-800 will clock DOWN to 333mhz or 667mhz effective. This means that any RAM you buy that is stock clocked higher then DDR2-667 will be clocked down to 667mhz.

Unless your planning on transferring the RAM to another machine in the future DDR2-667 is what you want. However the price difference between DDR2-667 and DDR2-800 is about $2-$3 a GB. So going with DDR2-667 over DDR2-800 won't make or break you either way. However DDR3 only seems to really shine in serious overclocking and with the new Core i7 systems and shouldn't be considered in other system types since it will just be clocked down to whatever you CPU core clock speed is.

In your case I would go with the 8gb of DDR2-800. Since whatever board you buy to support the Q9550 will not support the new Core i7 architecture however you may get another Q9xxx like the Q9850 (which I "think" has a core clock of 400mhz) or you may over clock your Q9550 later where it can take full advantage of the DDR2-800 speed RAM at which point the $15+/- will have been a very good investment.

 

[GhislainG]

jfurterer, where did you read that info? You can set your RAM to work at it's rated speed, overclock it or run it slower sort of independantly of the CPU FSB (though overclocking the CPU affect the FSBRAM ratio). Unless you overclock the CPU, DDR2-800 memory runs at the rated speed and timings, regardless of the CPU that's installed.

 

[jfurterer]

I found it here
http://www.overclock.net/amd-memory/235668-ddr2-memory-speeds-explained.html

It's a pretty extensive write up on how DDR2 works and what it means when you overclock with it.

 

[GhislainG]

That's accurate for an AM2 platform, but you referred to Intel Quad CPUs in your posts. The main difference is that an AMD CPU includes the memory controller. An Intel i7 might be similar, but the Q8200 and the Q9550 running at the default FSB will let you run DDR2-800 memory at 800 Mhz. If you overclock, then a lot of what he wrote also applies to the Intel platform.