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How much cfm should my cpu fan have for venice?

Posted: Fri Apr 29, 2005 5:53 am
by LazyAzN
Well yeah, I pre-ordered a 3200+ venice core... Thing is, I want to o/c from about 2.0 Ghz - 2.6 Ghz, so I am wondering, paired with my xp-90, without undervolting (preference), what is the best fan? Nexus's real silent fan, I don't know if it will help my cpu very well... I have a panaflo M1A right now, and its loud, just not too loud.

Posted: Fri Apr 29, 2005 9:22 am
by Ackelind
Try to get a fan that has a max rpm of about 1500-2000 rpm. I have a barebone with a 92mm fan and a HS similar to xp90, and it cools my prescott 2.8 to around 35 centigrates idle and 60 centigrades at load, when around 1000rpm. Sometimes after i've been gaming for a while and my GFX has put a lot of heat in the case, the fan goes up to 1500 rpm.

A venice should be a lot cooler at stock speed than a prescott.

Posted: Fri Apr 29, 2005 9:38 am
by ilh
Just poke around and see what folks are using for Winchesters. I don't believe the power consumption of Venice is very different from Winchester. I've seen initial reports of Venice using more power than Winchester and some lower.

I would think you could use a Nexus 92mm. I use a Zalman 7000B at minimum speed on a Winchester 3500+ at 240x10 with load temperatures of about 45C in a 31C case.

Posted: Fri Apr 29, 2005 2:17 pm
by LazyAzN
So would that mean a nexus 92mm real silent would do fine? Or should I spend $7 more and buy a papst? Btw I live in the US

Re: How much cfm should my cpu fan have for venice?

Posted: Fri Apr 29, 2005 2:42 pm
by Rusty075
Behold the power of math:

1: A64 Venice, at 2.4Ghz maxes out at about 60watts (according the Xbit's testing). Bumping up to 2.6Ghz, and assuming a bit of an OV, you're probably close to 70watts, max.

2: In our testing of the XP90, using a 92mm Nexus fan at 12, 7, and 5 volts, we got °C/W's of 0.28, 0.33, and 0.41, respectively.

3: Doing the math for your CPU, assuming a 30° case interior temp:
With the 92mm you can expect a max CPU temp of 50° at 12v, 53° at 7v, and 59° at 5v.

In other words, even running the nexus 92mm fan at a measly 5 volts will still provide plenty of cooling for that overclocked CPU.


That's why we put °C/W numbers in reviews. Isn't math neat? :lol:

Posted: Fri Apr 29, 2005 4:07 pm
by LazyAzN
Wow, I really need to learn more about this lol.

Course, as shown here... It doesn't look like it consumes 70w lol

http://www.pcper.com/article.php?aid=12 ... pert&pid=7

Posted: Fri Apr 29, 2005 5:34 pm
by Rusty075
LazyAzN wrote:Wow, I really need to learn more about this lol.

Course, as shown here... It doesn't look like it consumes 70w
The education continues.....

The pcper numbers include the entire system: CPU, mobo, ram, sound card, X800 vga, and the unknown losses from inefficiency in the PSU. That makes their numbers comparable only to the other cpu's they test in exactly the same system. (he measures the wattage "at the wall") But the nice thing about his numbers is that they should tell you to ignore anyone who tells you that you need a massive PSU for your upcoming system...even OC'd, running a benchmark that loads both cpu and gpu, it barely breaks 200 watts at the wall. That means that the system itself is probably drawing less that 150watts from the PSU.

The Xbit numbers are CPU only.

Posted: Fri Apr 29, 2005 6:19 pm
by LazyAzN
Wow, so ok, nexus will do fine for me, thx! Boy do I love reviewers :roll: