Socket 939 and DDR1

[kiosk]

I'm running an Athlon 64 3000+ on a Socket 939 Biostar NF4-UL A9 mainboard. The chipset is nForce4 CK8-04.

I have two 512MB memory sticks running in dual channel mode, they are DDR1-PC400 rated, and they are running very, very smoothly, even slightly above spec.

I'd like to add two more 512MB PC400 sticks to make up for a total of 2GB system memory.

However, I vaguely remember reading somewhere that certain AMD processors-chipsets-somethings - I can't remember! ...had trouble running four DDR1 memory sticks in PC400 mode, and that they would only run in PC333 mode.

Now, help me refresh my memory and tell me, if you know, if my system would be affected by this "feature", because I could end up wasting money on something that would actually make my system slower than it was before I started working on it.

[FTT]

Seems to me that 2 gigs of 333mhz would still be better than 1gig of 400 and that is assuming you are correct in the assumption that the memory would be downgraded one step. Usually it is the max memory capability that is less with the faster RAM, or loss of dual-channel capability. But that is more along the lines of around 3 or 4 gigs where the cutoff would be.

Check your manual to know for sure or Google for some reviews of your mobo to find out if your assumption is true. But I truly don't think there will be a problem even if it has to defer to one step down to the next slower speed.

I have an ASUS with a stipulation similar to that in an older series than yours so I assume it would not be an issue with your 'newer' BioStar.

[jlreich]

It is a glitch in the onboard memory controller in the CPU for the K8 series of CPU's (ie s939 and s754 AMD CPU's). It actually has nothing to do with the motherboard or chipset. And yes when all four memory slots are populated it will only run the memory at 333MHz.

However, with only 1GB in there now I agree with FTT that more is better than less faster ram. It does depend on what you are using the system for, but if it is anything that would benefit from more ram like games or video editing or rendering then more is better. Because if you run out of physical ram you end up going to virtual ram on the much much slower hard drive, so more slower ram is still way better than going to the hard drive. ;)

Ideally you would remove the 2x512MB and get 2x1GB and sell the 512's or use them in another system. But if that isn't practical for you then 4x512MB is good.

[kiosk]

Ideally you would remove the 2x512MB and get 2x1GB and sell the 512's or use them in another system.

And this is the reason two 512MB sticks can be bought for peanuts. Everybody wants 2x1GB.

Actually, the PC400 specification is holding me back a bit - I know the CPU is capable of MUCH higher speeds, but it's held back by memory-bound FSB. The computer is actually running a 215 MhZ FSB right now, but back when I had two 256MB PC333 sticks, the computer ran a 250 MhZ FSB (and was probably a lot faster than it is now - CPU-clock wise).

I'm mainly using the computer for number crunching so CPU speed is imperative.

Edit: seems like my processor has tons of potential - it's already overclocked 10%, and yet, it is rock solid undervolted at 1.125V (nominal voltage is 1.4V!) Temperature is 43C. All of this reminds me of a good old Celeron 300A. :)

[jlreich]

If you are using it for number crunching then 2GB is probably not needed.

[kiosk]

If you are using it for number crunching then 2GB is probably not needed.

True, but I neglected to mention that this number cruncher is also my main do-it-all box and I'm planning on going Win7 soon. I'll need that memory sooner or later - heck, I'm not running even half of my programs right now and XP has allocated 810 megabytes of physical RAM - that's not even counting what's in the swap file. ;)

[jlreich]

You had to know this was coming... But it's time for a core upgrade. If this is your main system and you are planning on moving to 7 it's time. 7 isn't the heavy hitter like vista is but it will use more ram than XP. If XP is already using the bulk of your 1GB then you need something more up to date.

s939 was a great platform in its day, but its day was several generation ago. I have actually given away two s939 systems including a X2 4200+ and 4400+. If you turn off all the eye candy in 7 it will probably run OK, but it is really pushing it.

There, I said it. :p Now you can say how it will be fine. And I am cool with that. :D