If going for a 333 Fsb CPU, will memory go at pc2700 speeds ?

[Mokmo418]

If going for a 333 Fsb CPU (socket A), will memory go at pc2700 speeds or pc3200 speeds ? (Given that the mem bar is a pc3200)

 

[EightySix Four]

probably 3200, depends on the mobo though.

 

[MDE]

The memory should run at PC2700. The system will run better with the FSB and RAM at the same speed.

 

[EightySix Four]

that really only holds true for pentiums, the athlon's are fine with it at different ratio.

 

[VirtualLarry]

I'm sorry, crazySOB297, but you are actually wrong on both counts.

On a Socket-A Athlon, one is much better running their RAM speed sync with the FSB speed, and for a 166Mhz FSB (DDR333), that would be 166Mhz RAM (PC2700) speed. A PC3200 DIMM should run fine even clocked down slightly. If the mobo supports it, one could theoretically run the CPU at 166Mhz FSB, and the RAM at 200Mhz, but performance would likely be worse.

 

[EightySix Four]

Well, I've never heard that, I've always heard that with athlon's it doesn't, and with the intel's it does, but for the time being I stand corrected.

 

[superkdogg]

Crazy, you may be 1/2 right. In my experience Athlon XP's perform just as well, sometimes a hair better while running memory @ 200 and FSB @ 166. Or 166/133, you get the picture. But if you starve that CPU for bandwidth, that's a problem-just like P4. I would defer to anyone with scientific benchies on this, but that's been my experience with simple benchies like Sandra.

 

[Mokmo418]

i don't really understand...
This is really a value combo
i'm going to buy a cheap mobo (a nice upgrade to OldRig in my sig) probably with nforce 2 chipset
it's going to have a 2400+ sempron (533 FSB) cpu and 512 MB of PC3200 ram
so will the memory run at PC3200 or PC2700 ?
Anyways the PC3200 is cheaper thant its 2700 counterpart... so the choice is obvious

i'm not in a hurry to order these parts but i'd like assembly to be done by march 14th (spring break... lots to do... far from NewRig)


EDIT sempron = 333 fsb my mistake

 

[aka1nas]

I don't think you will notice the difference between having the RAM @PC2700 or PC3200 tbh and running it asynch from the FSB prob negates any performance advantage.

Also, Athlons don't have a QDR FSB, so the Sempron is a 333FSB(166Mhz double-pumped) cpu, whereas later bartons are 400FSB chips(200Mhz double-pumped) /nitpick

 

[r00ki3]

 

[r00ki3]

the ram and cpu speeds are set in bios. and i have a 3200 barton with corsair pc3200 ram (both r meant for 200mhz fsb). however, i tweak my fsb ratio a lot depending on what i'm doing - higher for gaming and lower for long-term downloads; and there's little difference in performance.
so by all means, buy the pc3200 ram cuz it's cheaper, easier overclocked with that sempron if you want to, and still usable if you want to upgrade to a cpu with 400 fsbin the future.

 

[dug777]

Originally posted by: superkdogg
Crazy, you may be 1/2 right. In my experience Athlon XP's perform just as well, sometimes a hair better while running memory @ 200 and FSB @ 166. Or 166/133, you get the picture. But if you starve that CPU for bandwidth, that's a problem-just like P4. I would defer to anyone with scientific benchies on this, but that's been my experience with simple benchies like Sandra.

😛 i extensively benched when i bought a new 512 stick of pc3200 on my 2000+ (133fsb) and my sandra bandwidths & 3dmark01s were down when i ran the memory @400mhz rather than in sync...however these days i run @177*12 and my mobo will only let me run the mem in sync (cos it sucks 🙂 ) so any dilemma has gone away 4 me!