is 2-> 4 ballistix a sensible RAM upgrade?

[marlinman]

greetings all... first post here I think and I have to say I owe a poster to this board much: days of frustration trying to o/c ended when I discovered here that I must disable cpu spectrum spread!

 

Anyway! I have a dfi nf4 sli infinity w/ 2x512Mb Crucial BallistiX PC3200. I've just RMA'd one of the sticks which may be relevant as I'm not sure I'll get a stick of identical revision to replace it! Life (albeit temporarily) with 512Mb bites so I'm thinking now is a good time to upgrade. My question basically is:

 

IF I can source 2 identical sticks to those that are (or used to be) in my mb can I expect the only difference post-upgrade to be the quantity of ram available? i.e. all other factors will remain unchanged? And is this a sensible upgrade path given my setup is only 8-9 months old?

[Guest SPQQKY]

No, 4 sticks of memory is usually a big no no with AMD boards. It's a crap shoot whether or not it will work and it's often after you have to make some more than lackluster adjustments.

I would try to sell your current memory kit and get a 2 x 1GB kit.

[marlinman]

that's a shame... I see that 2x1Gb kits offer relatively loose timings :sad:

[wardog]

PC3200 2Gb DC kit is loose @ 2-3-2-5?

 

Seeing a sig under your posts might give us a better idea.

[Kingfisher]

Loose or tight , timings mean squat.

Mr. Games has a thread with some great information/results showing there really is no difference running 2-2-0-2 or 4-4-8-4 or 1T or 2T CR.

The on-chip memory controller on AMD socket 939 cpus perform better the higher they are clocked.

Any decent 2 GB kit(2x1024) will work fine running XP or Vista.

Crucial, OCZ, Corsair, Mushkin, G.SKILL, Patriot, GEIL.

With DDR RAM being is short supply, beggers are not and should not be choosers at this stage of the game.

If you have the time and skill you can run 4 sticks in your PC, You will have to experiment with your timings , it's just easier to go with 2 sticks. You will be forced to run 2T but it's no big deal.

[marlinman]

Seems the only cl2 2x1Gb kits for sale down here in New Zealand are the Mushkin high performance pc3200 ddr400 kit, and various pricier Corsair kits. I gather some feel (or felt) that corsair+dfi=bad. What's the feeling re Mushkin modules?

[Kingfisher]

Corsair and Mushkin are fine choices, if you want, look up Yellowbeard, he reps the Corsair section here at the street. Plenty of folks use Mushkin too, look over the stock and overclock databases for some more information.

[Guest SPQQKY]

Seems the only cl2 2x1Gb kits for sale down here in New Zealand are the Mushkin high performance pc3200 ddr400 kit, and various pricier Corsair kits. I gather some feel (or felt) that corsair+dfi=bad. What's the feeling re Mushkin modules?

 

Actually, Corsair is on the recommended list for my DFI mobo. Do not count out Corsair, an excellent choice. Never had any issues with their memory.

As Kingfisher said, don't limit yourself to tight timings, they won't make enough difference to fork out extra cash for. Keep an open mind and search the data base here for what's working well and what to avoid.

[Liqui3D]

Truth is with Latency much is made of numbers without understanding how they work. This quote is my Bible for understanding latencies. Lets dicuss 32-bit systems with DDR-SDRAM DDR2 is only slightly different, but this easier to understand...

 

Current systems read memory in 32-bit chunks, comprising four 8-bit bytes. CAS latency specifies the number of clock cycles required before the first byte can be read. After that first byte is read, the remaining bytes are read without latency, in one clock cycle each. For example, CL3 memory delivers the first byte after three clock cycles and the other three bytes in one clock cycle each. This memory timing is designated 3-1-1-1 and indicates that six clock cycles (3+1+1+1) are needed to read all four bytes. CL2 memory uses a 2-1-1-1 memory timing, and therefore reads all four bytes in five clock cycles (2+1+1+1). Similarly, CL1 memory uses a 1-1-1-1 memory timing and requires only four clock cycles to complete the read.

 

On that basis, one might conclude that CL2 memory is 16.7% faster than CL3 memory and CL1 memory is 33.3% faster than CL3, which is a substantial difference. In fact, that differential holds only for single 32-bit reads, whereas most reads are streaming. During streaming reads, each 32-bit read after the first is performed without latency. As the number of streamed 32-bit reads per access increases, the relative significance of the CAS latency overhead incurred for the first byte diminishes.

 

For example, compare a streaming 32-byte read (eight sequential 32-bit reads) with CL3 versus CL2 versus CL1 memory. With CL3 memory, the first 32-bit read requires six clock cycles. Each of the following seven 32-bit reads does not incur the CAS latency penalty, and so requires only four clock cycles. The full 32-byte read therefore requires a total of 6 + (7*4) or 34 clock cycles. With CL2 memory, the first 32-bit read requires five clock cycles, and each of the following seven 32-bit reads again requires only four clock cycles, for a total of 33 clock cycles. With CL1 memory, all eight 32-bit reads require four clock cycles each, for a total of 32 clock cycles. In this (very realistic) example, CL2 memory is actually only 2.9% faster (1/34) than CL3 memory, and CL1 memory is only 5.9% (2/34) faster than CL3.

 

 

 

 

Hope this helps

[Technohydra]

Yeah, ignore the timings. The only expception is 1T or 2T, as I always seem to see some difference between them. The trade-off is that you may have to disable 1T to get another, 300 mhz out of your cpu. The cpu getting an OC like that and losing 1T timing is a no brainer, the cpu clock will more than make up for the loss of CPC.

 

Ideally, you want to max out your cpu overclock, and then try to get your timings tightened from there. 1T, TCAS, TRAS, etc. you just tighten them up as much as possible at max cpu speed, with a priority on 1T command rate. Dividers are just fine if you want to keep the bus clock high and still run at tight timings and 1T. The order of importance is cpu clock, bus clock, memory clock, everything else. And arguably the first 2 are equaly important.

[red930]

It always seemed to me that 1T and 2T are a bit overrated... I accidentally put "Disable" for the CPC instead of "Enable", and I saw no difference in my real-world performance (word docs, surfing, and the occasional game).

 

But I'm probably wrong as usual :tooth:

[Kingfisher]

No, you are not wrong, there is no difference unless you are enching.