Another stupid CPU/RAM question

[xtknight]

Opinions needed (poll):

Should I just get a new 2x1GB stick set? I really don't want to waste the gigabyte I already have. I don't know if the (little??) performance hit the memory controller puts on me by having 3/4 sticks justifies me spending twice as much as I normally would to get two full new gigabyte sticks.

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I have a Winchester A64 3500+. What are the consequences of filling up the last two slots of memory? I have to both set my memory to work at 333 effective MHz AND set my command rate to 2T, or just one or the other? What are the performance hits of both of these? I heard if I used up 3 slots of memory instead of 4, I'd have to forgo my dual-channel for all the slots. Is this true? (I'm in a tough position now because I have 2x512 and I want to upgrade to 2GB somehow (thanks to Battlefield 2 and my extreme multitasking scenarios).) How does all this affect overclocking? If it's DDR333 I can't even overclock it beyond that so I'm stuck at 333MHz effective? Should I just get a new 2x1GB stick set? I really don't want to waste the gigabyte I already have. I don't know if the (little??) performance hit the memory controller puts on me by having 3/4 sticks justifies me spending twice as much as I normally would to get two full new gigabyte sticks. This is driving me crazy. I heard the Rev-E Athlon64s didn't fix the memory controller in this respect (so it can address four sticks without any consequences). One more quick question: what differentiates the San Diego core from the other cores? I need to catch up with this stuff.

Thanks

 

[JohnAn2112]

If you fill the 2 other slots, you'll be at 333 Mhz AND 2T command rate. As for filling one other slot, your system will not even POST with 3 slots filled. You can only post with 1, 2, or 4 sticks of memory. The best option for Clawhammer, Newcastle, and Winchester cores is to go ahead and use 2x 1GB sticks for 2GB of memory since you'll be at 400 Mhz and 1T command rate. Dropping to 333 and 2T will have a significant hit on the memory bandwidth compared to what you are running right now.

 

[xtknight]

Originally posted by: OCZ John
If you fill the 2 other slots, you'll be at 333 Mhz AND 2T command rate. As for filling one other slot, your system will not even POST with 3 slots filled. You can only post with 1, 2, or 4 sticks of memory. The best option for Clawhammer, Newcastle, and Winchester cores is to go ahead and use 2x 1GB sticks for 2GB of memory since you'll be at 400 Mhz and 1T command rate. Dropping to 333 and 2T will have a significant hit on the memory bandwidth compared to what you are running right now.

Thanks for the reply. I guess that solves the "get 1gb or 2x512" problem. Any idea of real-world performance hit versus theoretical memory bandwidth hit? What you're saying is I should get 2 new gigabyte sticks and the cost of doing that would be justified rather than running 4 sticks and the DDR333/2T consequence? I know the ideal solution would be to run 2x1GB but I really don't want to waste the powerful gigabyte of memory I (mistakenly) spent $240 on. 🙁 Ah well I'll just put it in my old PC and hope it's compatible. What I have to worry about now is that 2GB memory that I choose being compatible with my CPU's memory controller (AND my motherboard?). Is it rare for memory to be incompatible or is it quite common? I have to have 1, 2, or 4 sticks for my system to POST at ALL, even in single channel mode? Wow I'm surprised...I never knew that and even some frequenters here never mentioned that to me.

 

[Xcobra]

i was wondering...what would happen if you put on a 512 stick and a 1GB stick...would that work in dual channel?and 1@ T??

 

[JohnAn2112]

Originally posted by: xtknight

Originally posted by: OCZ John
If you fill the 2 other slots, you'll be at 333 Mhz AND 2T command rate. As for filling one other slot, your system will not even POST with 3 slots filled. You can only post with 1, 2, or 4 sticks of memory. The best option for Clawhammer, Newcastle, and Winchester cores is to go ahead and use 2x 1GB sticks for 2GB of memory since you'll be at 400 Mhz and 1T command rate. Dropping to 333 and 2T will have a significant hit on the memory bandwidth compared to what you are running right now.

Thanks for the reply. I guess that solves the "get 1gb or 2x512" problem. Any idea of real-world performance hit versus theoretical memory bandwidth hit? What you're saying is I should get 2 new gigabyte sticks and the cost of doing that would be justified rather than running 4 sticks and the DDR333/2T consequence? I know the ideal solution would be to run 2x1GB but I really don't want to waste the powerful gigabyte of memory I (mistakenly) spent $240 on. 🙁 Ah well I'll just put it in my old PC and hope it's compatible. What I have to worry about now is that 2GB memory that I choose being compatible with my CPU's memory controller (AND my motherboard?). Is it rare for memory to be incompatible or is it quite common? I have to have 1, 2, or 4 sticks for my system to POST at ALL, even in single channel mode? Wow I'm surprised...I never knew that and even some frequenters here never mentioned that to me.

I didn't say that the cost of 2x 1GB would be justified. That's up to you to decide. Your motherboard should support 1GB sticks. OCZ has some low latency 1GB sticks that run at 2-3-2-5 timings.

 

[JohnAn2112]

Originally posted by: Xcobra
i was wondering...what would happen if you put on a 512 stick and a 1GB stick...would that work in dual channel?and 1@ T??

That would not run in dual channel. For dual channel, the sticks need to be the same density and, most of the time, same IC's and timings.

 

[xtknight]

Originally posted by: OCZ John
Your motherboard should support 1GB sticks.

Yup my motherboard supports 1GB sticks but I was worried about it supporting the specific chipset on the memory that I'd choose. Is there a list of tested memory configs for OCZ memory? (Oh actually I did find one on ocztechnology.com but my motherboard's not in there. Ah well I'll look at ASUS' QVL page.) Isn't the on-die memory controller (for Athlon 64) also a factor in regards to whether a specific memory chipset is compatible or not? Thanks again for the help.