Importance of active VRM cooling?

tommybhoy · 3 Feb 2013 at 11:45

Rossi~ said:
Put it this way.
My 7970 doesn't like anything over about 70c on the VRMs when overclocking. It's very easy for them to get higher than that when pumping the volts.

Rossi~ said:
If you have a choice to actively cool them, do it.

+1

In matts AC 7970 Extreme thread and some others, vrm cooling was talked about quite a bit.

The cooler you can keep the 79s vrms, the better stability/higher clocks can be achieved.

Imo, vrm cooling is a major factor in 79 oc'ing, it doesn't matter how cool I keep the core, it flakes out when the vrms get too hot.

Uncle Petey · 3 Feb 2013 at 12:03

Agree with the guys that get issues at over 70c or so. 73c was my dodgy number too, especially in Heaven where it would start to artifact more often than not, though not always.

I put a hell of a lot of work into getting those temps down with custom aircooling. Got 'em down to 61c or so in Sleeping dogs extreme which would/could also artifact at over 73c or thereabouts.
The stock cooler would get into the 80's (or 90's with the side panel on). This is all when OC'd obviously.

Some users don't have an issue though.

weehamish · 3 Feb 2013 at 12:35

Just reading this im wondering why they don't aim to cool them from the start?

If your saying to get better ocing you need to keep them cooler more so then the core why don't amd and nvidia focus more on this then they could ship higher clocks as standard?

I think its just the way things are once you reach an oc when they get too hot that's your oc! Spending more money on the card is silly imo as it won't even add 5% performance from air to water. Water is mostly for noise or cases with crap air flow, well that's what im seeing anyways.

If you want to try save money just buy the best air cooled card with good vram cooling. The asus cards have it and also come with a separate bit of kit that you can attach to help keep them cooler.

The matrix will probs have the coolest vrams of all 7970s

Uncle Petey · 3 Feb 2013 at 12:37

VRAM and VRM are two different things

Gregster · 3 Feb 2013 at 12:40

Uncle Petey said:
VRAM and VRM are two different things

weehamish · 3 Feb 2013 at 12:41

That's what i was thinking but its still chips on the pcb? So its still something that could be looked at in manufacturing?

Because if it turns out to be true it must be at its peak or both nvidia and amd would focus around this?

whyscotty · 3 Feb 2013 at 12:42

Uncle Petey said:
VRAM and VRM are two different things

^^^
Damn you Speedy Gonzales - your too quick

whyscotty · 3 Feb 2013 at 12:44

pgi947 said:
Cheers Andy. Think I'll go for the alphacool blocks then

A little googling I found this, its not aimed at WC but dear god look at the VRM temps on that XFX 7970 DD!! Its shocking, worse than a reference cooler!!

http://www.hardware.fr/articles/853-17/thermographie-infrarouge-cartes-graphiques.html

WHAT!!!!! NO Heatkillers ? :eek:

Gregster · 3 Feb 2013 at 13:01

pgi947 said:
What is the melting point of copper?

1,085 °C

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; a freshly exposed surface has a reddish-orange color.

Symbol: Cu

Electron configuration: [Ar] 3d10 4s1

Melting point: 1,085 °C

Discovered: 9000 BC

Atomic number: 29

Atomic mass: 63.546 ± 0.003 u

That is off the top of my head

pgi947 · 3 Feb 2013 at 13:06

dave_beast said:
1200/1650mhz are my daily clocks

Mobile phone pic apologies, i've got the polished black one, it's basically a dark mirror finish.

VRM1 73ºc and VRM2 60ºc during a run of Heaven 3.0 at OcUK settings at the above clocks.

Thanks for the info dave

23c above core temp is a bit much for my liking, while investigating last night I found quite a few statements suggesting VRM temps should be +/- 5c of the core to get the best performance.

tommybhoy said:
+1

In matts AC 7970 Extreme thread and some others, vrm cooling was talked about quite a bit.

The cooler you can keep the 79s vrms, the better stability/higher clocks can be achieved.

Imo, vrm cooling is a major factor in 79 oc'ing, it doesn't matter how cool I keep the core, it flakes out when the vrms get too hot.

Thanks buddy

weehamish said:
That's what i was thinking but its still chips on the pcb? So its still something that could be looked at in manufacturing?

Because if it turns out to be true it must be at its peak or both nvidia and amd would focus around this?

Depends on the layout, if you look at the thermal imaging link I posted earlier, some custom designs (XFX DD) are absolutely pathetic, while the decent aftermarket coolers were keeping things a good 15-20c cooler then stock in the VRM area.

pgi947 · 3 Feb 2013 at 13:09

whyscotty said:
WHAT!!!!! NO Heatkillers ?

Its not a certainty, its more a cost issue, I priced up my rebuild the other night and rapidly hit £400 and that was even without tubing and fluid factored in. Sourcing stock of decent blocks is becoming a pain in the neck too....go take a look at OcUK's 7970 block stock levels, its near enough non-existant, as are many other places

gregster said:
1,085 °C

Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; a freshly exposed surface has a reddish-orange color.

Symbol: Cu

Electron configuration: [Ar] 3d10 4s1

Melting point: 1,085 °C

Discovered: 9000 BC

Atomic number: 29

Atomic mass: 63.546 ± 0.003 u

That is off the top of my head

lol

Hmmm 1000c, going to need a volt mod to hit that

I think thats decided then, active is going to be far more beneficial for me then non-active.

Gregster · 3 Feb 2013 at 13:15

Keep an eye on the MM Paul, I have a feeling there will be two MSI Lightning 680's going on soon, with water blocks already fitted

whyscotty · 3 Feb 2013 at 13:18

gregster said:
Keep an eye on the MM Paul, I have a feeling there will be two MSI Lightning 680's going on soon, with water blocks already fitted

Bring on the TITANS

Rusty0611 · 3 Feb 2013 at 13:22

Ha ha. I'm half tempted to get one as well.

whyscotty · 3 Feb 2013 at 13:24

Rusty0611 said:
Ha ha. I'm half tempted to get one as well.

Go on you know you want to

Gregster · 3 Feb 2013 at 13:28

It is the 384 bit bus that has my attention. I feel strangled at 5760*1080 with my cards and even if they are 50% faster than a 680, I will be getting 2.

pgi947 · 3 Feb 2013 at 13:30

gregster said:
Keep an eye on the MM Paul, I have a feeling there will be two MSI Lightning 680's going on soon, with water blocks already fitted

Haha, although I would love to bench some 680's, I really need to see what I can churn out of these cards first, especially as I'm actually enjoying crossfire for the first time in quite a while at the moment

whyscotty said:
Bring on the TITANS

Bring on the trail separation followed by being a weekend dad

*is pretty much whats going to happen if I grab a couple of Titans

* .

So this puts me back to square one, EK, Heatkiller or Aquacomputer.

weehamish · 3 Feb 2013 at 13:34

That's what im saying it obv can be done better so why don't they? It would cost them nothing really its just greed and cheapness why they don't.

Gregster · 3 Feb 2013 at 13:41

Still undecided. I can afford one but would idealy like to go with 2 from the off. They could be popular and sell out in no time at all and then I will be regretting waiting.

I know what you mean though PGI. I have had to explain how I need them big time. So long as the better half gets her Holiday, she will be happy

whyscotty · 3 Feb 2013 at 13:41

@pgi

check your trust