4x512MB CL2.5 or 2x1024MB CL3

[Tostada]

I've seen a couple posts referring to problems on dual-channel boards running 4 sticks of memory, but I haven't really seen many specifics. Is this just an NF4 issue? If this has been covered in depth before, feel free to tell me I'm an idiot who can't figure out the search function and point me to the correct thread.

I just gave away 512MB to someone who got a new machine that only came with 256MB, and I figured I'd replace it with 1024MB. I will probably be upgrading my main system within a couple months, and I may actually elect to go with 2048MB to try and improve performance with some work I do with multiple 2GB databases.

The current board is a single-channel Socket A board which can handle 2x512MB or 1x1024MB just fine. The question is: do I pay $90 for 2x512MB Corsair CL2.5 or $130 for 1x1024MB Corsair CL3?

If I move to 2048MB in two months, then I would buy more and be in the position of running either 4x512MB CL2.5 or 2x1024MB CL3.

There would have to be a pretty major performance penalty for running four sticks if I'm going to pay $90 more for CL3 instead of saving money and using CL2.5. Does anybody have some benchmarks to point me to?

Thanks.

 

[MobiusPizza]

NF4? I suspect you are using AMD CPU.
Memory controllers are Built-in in AMD Athlon64 CPU cores. Which mean it's not the chipset's problem.
Running 4 sticks off Athlon64 Winchester core would not allow the 1T timing; The new Venice core doesn't have this problem

 

[Gerbil333]

Originally posted by: AnnihilatorX
NF4? I suspect you are using AMD CPU.
Memory controllers are Built-in in AMD Athlon64 CPU cores. Which mean it's not the chipset's problem.
Running 4 sticks off Athlon64 Winchester core would not allow the 1T timing; The new Venice core doesn't have this problem

The Venice core still cannot run 4 double sided sticks of RAM at 1T. Four single sided sticks can run at 1T, but not double sided. And, unfortunately, single-sided 512mb sticks of RAM are rare

 

[Tostada]

Originally posted by: Gerbil333

Originally posted by: AnnihilatorX
NF4? I suspect you are using AMD CPU.
Memory controllers are Built-in in AMD Athlon64 CPU cores. Which mean it's not the chipset's problem.
Running 4 sticks off Athlon64 Winchester core would not allow the 1T timing; The new Venice core doesn't have this problem

The Venice core still cannot run 4 double sided sticks of RAM at 1T. Four single sided sticks can run at 1T, but not double sided. And, unfortunately, single-sided 512mb sticks of RAM are rare

So can someone tell me what this means? Would two 1024MB CL3 sticks be better? Are there any benchmarks?

 

[Arcanedeath]

Yes 2 1024mb DS CL3 dimms would be better than 4 of any other type of dimms because you are forced to run a 2T cmd rate w/ 4 sticks, and this kills performance more than any other single factor.

 

[ohnnyj]

But this is an AthlonXP we are talking about here.

 

[Arcanedeath]

What motherboard and chipset do you have? we need this info to tell you if 4 dimms is going to make a diff or not, In general on the desktop unless you are on an Intel Platform (I865, I875, or I915) you do not want to run 4 dimms because it forces your memory speed down to 333 or drops your cmd rate from 1 to 2T on the A64 systems, AXP if you have a Via chipset like KT600, in some cases you can get away w/ 4 dimms and not suffer a performance loss if they are quality dimms and you have a good motherboard, but in most cases you should stay w/ 2 dimms and get it over with.

 

[Gerbil333]

Originally posted by: Arcanedeath
Yes 2 1024mb DS CL3 dimms would be better than 4 of any other type of dimms because you are forced to run a 2T cmd rate w/ 4 sticks, and this kills performance more than any other single factor.

How much does it kill performance, disregarding benchmarks? I'm stuck in a similar boat. I have a set of Kingston 2x512mb HyperX PC3200, and I'm willing to throw in another set when I buy a socket 939 board in a few weeks, but not if the performance hit will be noticeable.

 

[Tostada]

The memory would currently be going into an Athlon XP 1600 on a KT333 board, but I'm just talking about a single 1GB or two 512MB sticks, so that's not really the issue.

In a few months I'll be rebuilding my main system with a Socket 939 board, and I will probably take the memory out of the XP 1600 and then adding to it. So I'm really asking a long-term question here. In a few months, I will be putting together an A64 system with either 4x512MB or 2x1024MB. I just want to get something now (either 1x1024MB or 2x512MB) which I will put into the KT333 board but then be able to recycle when I make a new A64.

Sorry to sound so clueless. I just haven't heard anything about this 1T command rate before.

 

[Arcanedeath]

Command rate is a memory timing similar to cas latency but more important, in your case you should get 1 x 1024mb as you'll be moving to A64 later and having more than 2 dimms w/ a64 is a no no

 

[Gerbil333]

Can you see the difference between 1T and 2T in games? In general computing? In encoding? How much? I don't care about benchmarks anymore.

My K7S5A with 1GB of 2.5-3-3-6 RAM outperforms any of my nForce 2 boards in games if they only have 512mbs of RAM installed, even if the nForce 2's have a faster CPU and 2-2-2-5 memory. The K7S5A is surely 10% slower than the nForce 2 machines, but the additonal RAM gives it a huge advantage.

 

[imported_burningrave101]

Originally posted by: Gerbil333
Can you see the difference between 1T and 2T in games? In general computing? In encoding? How much? I don't care about benchmarks anymore.

My K7S5A with 1GB of 2.5-3-3-6 RAM outperforms any of my nForce 2 boards in games if they only have 512mbs of RAM installed, even if the nForce 2's have a faster CPU and 2-2-2-5 memory. The K7S5A is surely 10% slower than the nForce 2 machines, but the additonal RAM gives it a huge advantage.

1T vs 2T will make a bigger difference then any other timings will such as CAS latency. Your better off going with 1GB modules. Buying 4 512MB sticks is a waste of time and leaves you no upgradeability. You can get Corsair Value 1GB sticks for around $100 each and they should be able to run 3-3-3-8.