AMD Gurus: Whats the diff between Athlon 4000+ and FX-53?

montrealbreaks · Post by **montrealbreaks** » Wed Jul 13, 2005 5:32 pm

Hey all. For those AMD folks out there, can anybody tell me what the difference is between the Athlon 4000+ and the FX 53?

The FX 53 is about $300 more expensive, but both chips appear similar in specs on Directpc.ca (I was fantasizing about an XPC and building a dream machine). So, the 4000+ isn't the mobile version, it's the desktop verison. Anyways, the listed specs are:

AMD Athlon 64 4000+ (2.4 GHz) 1024KB cache 939-pin
AMD Athlon 64 FX-53 (2.4 GHz) 1024KB cache 939-pin

Obviously, with identical speed, cache and both using socket 939, there must be SOME difference to justify the price... Is it the FSB speed? What?

Any advice appreciated.

LukeDz · Post by **LukeDz** » Wed Jul 13, 2005 10:29 pm

I believe the FX-53 is better suited for overclocking.

AdamJay · Post by **AdamJay** » Wed Jul 13, 2005 10:52 pm

yes, the FX series have unlocked multipliers. the multiplier multiplies the FSB to get the core speed of the CPU.

so 200mhz (which is the FSB) x 12 (which is the multiplier) = 2400mhz or 2.4ghz.

now, on the 4000, the multiplier is locked, so the only way to overclock would be to increase the FSB. 210mhz FSB on the 4000 would have it performing at 2520mhz or 2.52ghz. Thats a pretty standard overclock speed for the 4000. However you can only overclock by way of increasing the FSB so high before it becomes unstable or unsafe, also by increasing the FSB, you are going to be wearing down your RAM faster. DDR400 RAM (PC3200) is for 200mhz FSBs, a 210mhz FSB would have that ram performing at 420mhz (DDR420), the higher you go the higher the likelihood that your RAM will fail.

So the next step in (safe) overclocking is to have a chip with an unlocked multiplier and that is exactly what the FX series chips have. By overclocking via multiplier rather than FSB, your ram isn't pushed as much and so long as you have adequate cooling, neither is the core of the cpu.
so to obtain 2500+mhz with the FX series chip, you adjust the multiplier from 12 to 12.5. With (expensive) liquid cooling, one could get the FX to as high as 2900mhz and beyond.

jahnlay · Post by **jahnlay** » Thu Jul 14, 2005 1:09 pm

AdamJay, you and Horatio Kain from CSI Miami are my new heroes! (We just saw the episode where Horatio dumps the DA chick because she made a deal with a criminal)

"Your Kung-Fu is strong", "The Force, strong with this one it is"!!

montrealbreaks · Post by **montrealbreaks** » Thu Jul 14, 2005 4:14 pm

Gawsh!

Thanks for the info Adam. Top notch! This is all fantasy right now, I'm nowhere near able to buy a new computer - but it's nice to know!

I think for a teensy little XPC I'll stick with a 4000+, there's no need try to overclock all that when it's stuck in a toaster size case... That's probably just asking for trouble!

UNLESS... You were to DECREASE the multiplier on the FX chips so as to increase stability and reduce heat... For performance perhaps? I mean really, I've got LOADS of CPU headroom with my current 3200+ notebook. Is this a resonable idea, or am I being a corn-fed idiot?

mikemc · Post by **mikemc** » Thu Jul 14, 2005 7:05 pm

montrealbreaks wrote: UNLESS... You were to DECREASE the multiplier on the FX chips so as to increase stability and reduce heat...

what if the multiplier was *negative* .... holy crap! I think you just discovered time travel...