Underclocked/Undervolted AthlonXP vs VIA 1.2GHz Nehemiah?

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SilentStef
Posts: 23
Joined: Sat Dec 18, 2004 3:00 am
Location: Vancouver, BC, Canada

Underclocked/Undervolted AthlonXP vs VIA 1.2GHz Nehemiah?

Post by SilentStef » Sat Dec 18, 2004 4:27 am

Hello all

I've spent several hours reading many of the informative posts in these forums and need some help on my way to putting together my first SilentPC(tm). The computer I am replacing is a very old PII 233MHz machine that is incredibly noisy. This computer primarily sits idle. I am running windows 2000 pro and various web serving software (private web/ftp server) including Apache and mySQL. The computer is used when someone connects remotely (very rarely, but handy) or my wife uses the computer for web surfing and email. The rest of the time it just wastes energy... Since this computer spends most of it's time sitting idle I want a computer that consumes very little power, makes very little heat, and no noise when it's idle. I can tolerate a little noise when it's running. Future uses for this computer will include some video editing (mainly downloading home video footage through firewire and burning to DVD), but no plans for games.

I was initially planning to purchase one of the VIA mini-itx boards because they are low power/heat, can be run passively, and are awfully tiny. I was willing to live with the poor performance given the low power consumption until I ran across an article on toms hardware guide showing a 4.5W idle power for AthlonXP processors bridged to act like an MP processor. Further reading on this site showed a similar experience and I've read alot of threads about Cool'n'Quiet technology on the Athlon64 processors and how lots of people are making low noise systems with their Athlon64's running at 1GHz. However, I have not been able to find the answers to some questions and I'm hoping someone can help me out or point me in the right direction to find the answers I'm looking for.

Questions:

1. To quote from Deep UnderVolt/Clock: 4.7W CPU PC:
It would be interesting to know if Mobile XPs, Athlon 64s and Intel CPUs can provide such a wide range of performance and energy consumption. This consumption appears little more than VIA CPUs. [Editor's Note: Actually less than most of the current stock-clock VIA.]
So, can an Athlon64 processor be underclocked/undervolted to idle at such an extremely low power? The AthlonXP mentioned in the toms hardware article was only operating at 300MHz. Has anyone tried to run an Athlon64 at 300MHz?

2. Much ado has been made of processor power consumption, but what about consumption of the entire system? Does an idling EPIA a system consume less power than an "identical" idling (4.5W) Athlon system (with a plain jane cheapo 2D video card, but same storage devices)?

3. Comparing the benchmarks results from tomshardware (for the 300MHz Athlon) to the benchmarks results from mini-itx.com (for the Nehemiah 1.2GHz) it looks like an underclocked AthlonXP running at 300MHz is a slightly better performer than the Via running at 1.2GHz. It's hard to tell though because while the two reviews use some of the same programs in their benchmarks (SiSoft, PCMark, 3DMark, etc) they are using different versions (PCMark 2003 vs 2002, etc). Also the Athlon system had an unfair advantage in the video card department. Anyone know of a more direct head to head comparison?

4. Speaking of video cards, is there a way to shutdown the video card completely when the screen saver is active or when powersave kicks in? That would allow me to use a decent video card (underclocked and passively cooled...) without any heat or power consumption. Think the motherboard be hacked for that without causing damage to the video card?

I'm really liking the idea of throttling the processor when the computer is idle to consume less power, and make less heat and noise, yet still be able to run at full speed on demand. I want to make sure that I can keep the power consumption low once a video card and harddrive are added to a motherboard that's capable of good undervolting. I assume that I'm not going to find anything smaller than ATX in the motherboard department, but won't know till I settle on a plaform and go looking. Size isn't a big issue, but smaller would be better.

The AthlonXP Processor @300MHz is doing 4.5W idle and less than 15W fully loaded. The Via System is doing 16W idle and 28W full load. Would be awesome if I could do as well with a complete Athlon system. Anyone have any insights?

Thanks,
Stef

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