What PSU? P4@3Ghz

**stepir** · 11-29-2005, 03:13 AM

Hi,

What PSU would you choose to power a P4 system and to be sure to avoid any problems with power consumption?

I did a power simulation of my system and I need at least 200W, so I'd like to have a PSU able to give me at least 300W. Is there any DC-DC Psu able to do that or do I have to go on an inverter solution and use a normal ATX PSU of a dekstop pc?

Thanks

Ste

**EsKALad** · 11-29-2005, 03:19 AM

look into dsatx i think its called? honestly a 3.0 p4 is overkill for a car. i personally think anything over 2.0ghz is overkill. between 1 to 1.5ghz is good. and you can use smaller psus and cases and they are more stable less heat and all that good stuff.

**MatrixPC** · 11-29-2005, 10:00 AM

Total wattage doesn't mean any ****.
From the power calculator you use, write down how many amp on each power rail (12v, 5v, 3.3v) and compare it to the spec of the PSU. Currently DSATX is the most powerfull one.
If your calculation required 15A or so on 5V rail, your only choice is INVERTER. DSATX max out at 10 or 12A I can't remember.

**Nicorolla** · 11-29-2005, 10:23 AM

well, you already have one problem
P4 3ghz = massive power consumption, no getting around that
if you do choose to go that route, going with a standard PSU and inverter is ur only way.

if you want high processing power with low power consumption go with either Athlon XP-M or Pentium M chips. They are a bit more money tho

**Dylan98R/T** · 11-29-2005, 01:18 PM

Originally Posted by Nicorolla

well, you already have one problem
P4 3ghz = massive power consumption, no getting around that
if you do choose to go that route, going with a standard PSU and inverter is ur only way.

if you want high processing power with low power consumption go with either Athlon XP-M or Pentium M chips. They are a bit more money tho

Depends, I got a XP-M 2400+ off Ebay for $25 and it will clock 10 x 210 easily. It will also easily scale down to 1.1v at 1000mhz which is all I really need in the car anyway. 8rdavcore is a great program for running AMD speed on a as needed basis.

The P-M are more expensive.

**jerico2day** · 11-29-2005, 02:12 PM

The northwood p4s consume exceptionally low amounts of power as well. Though 800fsb versions are hard to come by, they run on ebay about the same price as cheaper prescotts. They're not available in Socket T though (afaik).

Case in point, I was able to overclock a celeron northwood 20% (2.26ghz to 2.80ghz). And at the same time I *lowered* the voltage in the process. So it runs cooler, faster, consumes less power, and just as stable than stock.

**Dylan98R/T** · 11-29-2005, 03:06 PM

Originally Posted by jerico2day

The northwood p4s consume exceptionally low amounts of power as well. Though 800fsb versions are hard to come by, they run on ebay about the same price as cheaper prescotts. They're not available in Socket T though (afaik).

Case in point, I was able to overclock a celeron northwood 20% (2.26ghz to 2.80ghz). And at the same time I *lowered* the voltage in the process. So it runs cooler, faster, consumes less power, and just as stable than stock.

Yep. A [CPU work] / [watt] graph would be best to determine which processor is more efficient.

My northwood will run a 650mhz overclock on stock voltage (as my MB does not have adjustment).

**Nicorolla** · 11-29-2005, 04:25 PM

i can't wait t'ill pentium m based architecture becomes mainstream and at affordable prices. I've seen some articles about the M chip overclocked beating the top end desktop processors from both AMD and Intel... and still drawing only like 20w or 30w, don't remeber exactly.
The ultimate carPC (right now) would be one of those new Aopen desktop boards that supports the Pentium-M chip and a decent mid end video card.
If i had tones of money to dish out, i would buy one in a hardbeat

Dylan98R/T - sorry i wasn't very clear, when i meant more expensive i meant price/performance/efficiency wize, altho i'll have to agree that the XP-M is the best bang for the buck when it comes to this. I'm just curious, how many amps is ur whole carPC drawing at full load with that chip?

**Dylan98R/T** · 11-30-2005, 03:07 PM

Originally Posted by Nicorolla

Dylan98R/T - sorry i wasn't very clear, when i meant more expensive i meant price/performance/efficiency wize, altho i'll have to agree that the XP-M is the best bang for the buck when it comes to this. I'm just curious, how many amps is ur whole carPC drawing at full load with that chip?

I agree if you are buying NEW hardware, the mobile version of any chip is more expensive. But I don't know why anyone would want to buy the most current hardware for a carPC anyway. Let that stuff become 6 months old and the price is half.

I paid $90 for a used P4 2.66 and $25 for a used XP-M 2400+. The XP-M is comparable in performance to the P4 at lower wattage. Especially given I can use 8rdavcore on my M7NCG400 and dynamically run the XP-M at lower than OEM voltage (I can hit 1.1v on mine) and lower speed. I'd like to compare the P4 with XP-M but I can't undervolt my P4 MB. The northwood is an efficient chip but for several reasons the XP-M is going in the car.

Mine system isn't together completely, but afterwords I'll have some system draw numbers at different speeds.

**Nicorolla** · 11-30-2005, 04:49 PM

Originally Posted by Dylan98R/T

Mine system isn't together completely, but afterwords I'll have some system draw numbers at different speeds.

yeah i'm very curious to see what kind of numbers you can get, everyone keeps talking about this is more efficient that this and **** like that but they don't have numbers to compare. What you have there is "the" way to go with a carPC price/performance/efficiency wize. Unfortunate for me i never concidered power efficiency until a while after i made my carPC. I'm just waiting for new technologies come along, like the P-M but cheaper... and made by AMD

Until then, i'll just have to torture my yellow top batt.