OCing the A64 2800, 3400 performance??

[stelleg151]

I have yet to find an in depth review of overclocking the Athlon 64 2800+. I am optimistic about it, because the results of the benchmarks of 3000+ at 2.45 ghz showed it to be better than 3500 performance, so I am curious about the 2800, because to me it looks just like the same processor but lower clock, due to lower multiplier, and I understand therse NO WAY to increase the multiplier on the 64's. That sucks a lot. But yeah if anyone knows anything about seriously overclocking the 2800 I would love to hear.

Thanks,
Mr. Jorge

 

[Concillian]

The 2800+ should be a decent buy if you couple it with a motherboard that can do very high FSB speeds. You'd need to run in the 260+ range for FSB to get the same speeds that happen on the 3000+ processors. This means you have to be a little more worried about RAM and such.

The 3000+ is so nice because 2400 MHz is 240 FSB is 200 MHz RAM on a 5:6 ratio. 2500 MHz is 250 FSB is 208 RAM, which is a reasonable overclock to expect from PC3200.

for a 2800+ at 2400 MHz you're at 267 FSB and you have to choose between 218 RAM (a bit of a stretch for most value PC3200) or 172 RAM, which is quite a bit slower than PC3200.

the 3000+ is a better match in most cases, you either get PC4000 and run 1:1 or you get PC3200 and run 5:6. The RAM issue is a little less clear cut with the 2800+, you need something like 433 to be in the right range for a 5:6 ratio. But for the price of a 2800+ I doubt you can go wrong. There are less statistics about where a 2800+ can reliably get in terms of clock speed, but it seems all the newcastles are ending up between 2300 and 2500 on air and reasonable voltages.

In many cases it can actually be cheaper to get the 3000+ and stick with PC3200 and a 5:6 ratio. It's easy to drop an extra $30 on RAM when you go shopping for stuff greater than PC3200 speed.

 

[stelleg151]

Thanks, and good point, and do you have any idea of what kind of performance hit a 6:5 ratio or a 5:4 ratio has compared to a 1:1, because I read that there are connection lapses or something that arent there with a 1:1.

Thanks

 

[Jeff7181]

Originally posted by: stelleg151
Thanks, and good point, and do you have any idea of what kind of performance hit a 6:5 ratio or a 5:4 ratio has compared to a 1:1, because I read that there are connection lapses or something that arent there with a 1:1.

Thanks

I want to know too... my finger is hovering over the Ad to Cart button on a Chaintech VNF3-250 and either an A64 2800, 3000, or 3200.

 

[digiram]

I'd get the 3000 b/c of the 10x multiplier, and more cache is only needed if you're doing alot of encoding and stuff.

 

[BW86]

o0o0o0h i have the vnf3 and the 3200 with pc3200 mushkin value ram and its clocked to 2.475(11x125) @ 2.8v 1:1 2.5-4-4-8. default vcore.

EDIT: also with the new bios you can lower ur multi

 

[StealthElephant]

Digi: How do you know the 3000+ has a 10 multiplier? Is the stock FSB always 200mhz on the cpu?

So the 3200+ would have an 11 multiplier?

 

[Jeff7181]

Originally posted by: StealthElephant
Digi: How do you know the 3000+ has a 10 multiplier? Is the stock FSB always 200mhz on the cpu?

So the 3200+ would have an 11 multiplier?

Correct... all Athlon-64's have a 200 MHz "FSB"

 

[StealthElephant]

Is there a reason why 10 is a preferred multiplier?

Seems like people are pushing REALLY high FSBs, like 250+ FSB. Now the 3400+ 1mb L2 would have an 11 multiplier. To hit 2.4ghz would only require around 220FSB. What exactly would lowering the multiplier to 10 and jacking the FSB even more help? Why would you want to raise the FSB more if a higher multiplier is available since the ram to run that kind of FSB is more expensive.

 

[BW86]

The FSB (or, for AMD processors, the HTT*), or Front Side Bus, is the channel through which your memory controller communicates with your CPU. The FSB speed also indirectly affects the PCI/AGP bus speeds, which are arrived at by using a divider of the FSB speed. This means that the vast majority of the components in your system are reliant on the FSB to communicate with your processor. So, obviously, the faster your FSB can run, the faster your entire system can run.
-said by Ariste

heres the link Text

 

[StealthElephant]

I thought that you didn't want to change the AGP/PCI speed too much since it would cause problems, and that is why there are AGP/PCI locks.

 

[BW86]

The FSB speed also indirectly affects the PCI/AGP bus speeds...