New via c7-m ULV ? xp-m superunderclocked?

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[H]F Junkie
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Anyone seen the specs on this ? 3.5W....sounds very very tasty esp for making my own super small car pc's, routers, etc. Anyone seen pricing or availability ? The built in encryption engine is supposed to be very good also.

For something that has a little more power leeway, what do you guys use ?

According to This an xp-m 2500+ barton @ 600mhz/1.25v = 11W and at 1v = 7W

What is the lowest multiplier xp-m's can be? I don't think they'd ever hit 3W. If you can throw it at 4 * 100 for 400 (400 * 1v = 5W) that would be awesome also. I wonder how it would compare to the ULV? I imagine it would be slower at the same power consumption...thoughts?

Rob
 
Off the top of my head, it's 7x or thereabouts. Maybe 7.5x. IOW, 7.5x100=750MHz.
 
Yeah I know i've gotten 6 on xp-m's, hmm...

Wonder if it would run at 1V ? what motherboard can go that low ? :)
 
I have a 2400 XP-M on a Abit NF7 Ill check to see how low the voltage goes for you.
 
Low power socket A would be Geode NX, they are tough to get for cheap right now, ~650 USD on the Sis 741 "Eagle" platform...
 
According to This an xp-m 2500+ barton @ 600mhz/1.25v = 11W and at 1v = 7W
Click to expand...

That should be about right. This is using a simple formula that requires only a single point of data:

CMOS power is proportional to the frequency and the voltage squared

Thus, calculating the power usage for an underclocked and undervolted processor would require you to know the power usage at stock speed, and then multiply that by the proportional change.

For example, the XP-M 2500+ Barton uses 45w at full load, stock settings (1867 MHz, 1.45v). At 600 MHz, 1.25v, it uses the following:

45w * (600 MHz / 1867 MHz) * (1.25v^2 / 1.45v^2) = 10.75w

45w * (600 MHz / 1867 MHz) * (1.1v^2 / 1.45v^2) = 8.32w

You can use this to scale any processor. In fact, there are BETTER processor cores out there for underclocking and undervolting, like the Athlon 64 Socket 939. Tom's Hardware measured the DC power at load for a Winchester Athlon 64 3200+ at 30w. Most of them can clock at 1.0 GHz, 1.0v or lower:

30w * (1000 MHz / 2000 MHz) * (1.0v^2 / 1.40v^2) = 7.65w

You can imagine if you crank it down to 600 MHz, it will sip only 3w. The Mobile Barton has got NOTHING on 90nm Athlon 64 cores.
 
omega-x said:
Price?
Click to expand...

True :D

There are some nice deals involving a Biostar board plus a Geode NX out there. It's just that, if I were building a low-power box, I'd try to build it with an Athlon 64.
 
cool

using that formula, my turion uses only ~6 watts at 0.85v and 800mhz

originally 35 watts 1600mhz 1.45v
 
mike_6289 said:
cool

using that formula, my turion uses only ~6 watts at 0.85v and 800mhz

originally 35 watts 1600mhz 1.45v
Click to expand...

Actually, your Turion uses slightly less than that at stock speed. The TDP of 35w for Turion ML series is a general limit for all processors in the series. That means Turion ML processors clocked as fast as 2.2 GHz also use 35w or less at max load.

This is how AMD marks thier processors...it makes it easy for OEMs to design their cases and cooling systems for the worst case, so they can reuse those cases and cooling systems for all their AMD products.

You're close enough, though. Even with this data point, your power consumption is still 5w at load. At idle, about 2w.
 
What do you think of this ?
http://www.newegg.com/Product/Product.asp?Item=N82E16819104249

Could I clock this down to 500 or 600mhz?

This also looks interesting but is a lot more expensive:
http://www.newegg.com/Product/Product.asp?Item=N82E16819103523

Anyone know of a good 939/754 motherboard that is perhaps microatx and lets me put 1v or less into the cpu? Have to be able to change multis also ;)

defaultluser said:
That should be about right. This is using a simple formula that requires only a single point of data:

CMOS power is proportional to the frequency and the voltage squared

Thus, calculating the power usage for an underclocked and undervolted processor would require you to know the power usage at stock speed, and then multiply that by the proportional change.

For example, the XP-M 2500+ Barton uses 45w at full load, stock settings (1867 MHz, 1.45v). At 600 MHz, 1.25v, it uses the following:

45w * (600 MHz / 1867 MHz) * (1.25v^2 / 1.45v^2) = 10.75w

45w * (600 MHz / 1867 MHz) * (1.1v^2 / 1.45v^2) = 8.32w

You can use this to scale any processor. In fact, there are BETTER processor cores out there for underclocking and undervolting, like the Athlon 64 Socket 939. Tom's Hardware measured the DC power at load for a Winchester Athlon 64 3200+ at 30w. Most of them can clock at 1.0 GHz, 1.0v or lower:

30w * (1000 MHz / 2000 MHz) * (1.0v^2 / 1.40v^2) = 7.65w

You can imagine if you crank it down to 600 MHz, it will sip only 3w. The Mobile Barton has got NOTHING on 90nm Athlon 64 cores.
Click to expand...
 
does underclocking one of these processors affect its ability to automatically throttle its power usage?
 
cranberrie said:
does underclocking one of these processors affect its ability to automatically throttle its power usage?
Click to expand...

Most motherboards wil not let you enable Cool 'n Quiet if you alter the voltage, and that is one of the biggest benefits of underclocking - reducing the voltage.

That said, if you are clocking down in the range of 1.0 GHz or less, then you're already at the speed your processor is clocked to when idle under Cool 'n Quiet. In other words, you're not missing anything.

Still, if you want more control over your voltages and frequencies at load and idle, I'm told CrystalCPUID can let you create your own settings that work like Cool 'n Quiet. I believe you have to leave CrystalCPUID running in order for this to work, though.

I'm not sure how well that feature works though, I just use CrystalCPUID to change multipliers and voltages on the fly.
 
defaultluser said:
Most motherboards wil not let you enable Cool 'n Quiet if you alter the voltage, and that is one of the biggest benefits of underclocking - reducing the voltage.

That said, if you are clocking down in the range of 1.0 GHz or less, then you're already at the speed your processor is clocked to when idle under Cool 'n Quiet. In other words, you're not missing anything.

Still, if you want more control over your voltages and frequencies at load and idle, I'm told CrystalCPUID can let you create your own settings that work like Cool 'n Quiet. I believe you have to leave CrystalCPUID running in order for this to work, though.

I'm not sure how well that feature works though, I just use CrystalCPUID to change multipliers and voltages on the fly.
Click to expand...

Actually, I'm looking for a board that lets you do the changes in the bios, unless crystalcpuid works under linux & freebsd.
 
Robstar said:
Actually, I'm looking for a board that lets you do the changes in the bios, unless crystalcpuid works under linux & freebsd.
Click to expand...

Take a look at this thread on SPCR's forum:

http://forums.silentpcreview.com/viewtopic.php?t=29036

It details some good silent computing motherboards, and one of the attributes they like to nail down is undervolting support.

That said, are you nuts? Linux geeks LIVE for this stuff. There has probably been an equivilant utility to CrystalCPUID since time began.
 
Robstar said:
Anyone seen the specs on this ? 3.5W....sounds very very tasty esp for making my own super small car pc's, routers, etc. Anyone seen pricing or availability ? The built in encryption engine is supposed to be very good also.

For something that has a little more power leeway, what do you guys use ?

According to This an xp-m 2500+ barton @ 600mhz/1.25v = 11W and at 1v = 7W

What is the lowest multiplier xp-m's can be? I don't think they'd ever hit 3W. If you can throw it at 4 * 100 for 400 (400 * 1v = 5W) that would be awesome also. I wonder how it would compare to the ULV? I imagine it would be slower at the same power consumption...thoughts?

Rob
Click to expand...


New via C7-M on the Jetway Mini ITX C7 boards go from a multi of 10-15 ( 1GHz - 1.5GHz) w/ 400FSB. Haven't had a chance to overclock yet as I don't want to mess with my inventory. I know I had a Jetway C3 1GHz running smoothly at 1.2GHz but it was definately running hot at that point. The new Jetway C7 boards seem to run a lot cooler so they should offer more potential.

-Shawn
 
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