Phenom II 965 Overclock (with 3 5870s)

[microterf]

Ok, I have a new PHenom II 965 watercooled now, Seems stable at 4.0 GHZ now. 200*20. 1.485 volts. Max temp seems to be around 46*C after a couple hours of prime95. 2 Questions,

1. Is that about the max 24/7 clock I'll get out of this cpu
2. Is this processor just a total bottleneck to the 3 5870s? It seems the only real thing I notice is that going from the 2nd to the 3rd GPU it seems to raise my min frame rates in games.

 

[andy5174]

1. Yes and 3.8GHz in most cases.
2. Absolutely. You need at least an i5-750 for HD5870 in 2/3-way CF.

 

[Raidur]

Yeah I'd say there would be a bottleneck too, but then again tri-fire usually doesn't scale nearly as well as crossfire and the 5870 drivers are still pretty young.

See if your FPS drops if you downclock your CPU. This would mean you probably have somewhat of a bottleneck (depending on the game of course), this shows us if you had a faster CPU you'd get more frames (possibly), where if your GPU was the bottleneck you would see a very slight (if any) increase when overclocking.

Still a nice setup though, if you are water-cooled and getting that low of temps I'd totally keep 4.0ghz 24/7, especially with trifire 5870s.

 

[jimmysmitty]

Well air is more likely to only top out at 3.8GHz but water I have seen some hitting 4.4GHz stable.

The biggest problem would be the 3 GPUs. They will create a lot of heat even though they are going to be venting out the back plus depending on the chipset you got, you might hit a limit.

 

[lilotimz]

andy5174 wrote :

2. Absolutely. You need at least an i5-750 for HD5870 in 2/3-way CF.

LOL

LOL indeed. An i5-750 would be bottlenecked cause of the 16 pci-e lanes.

You need an LGA 1366 for any 3 way sli/crossfire cards to get its full potential...

assuming you have money for 3 5870s, you better have money for an i7...

*thinks back to the contest where the lga 1156 i7-860 was the weakest link for $2500*

 

[microterf]

andy5174 wrote :

2. Absolutely. You need at least an i5-750 for HD5870 in 2/3-way CF.

LOL

LOL indeed. An i5-750 would be bottlenecked cause of the 16 pci-e lanes.

You need an LGA 1366 for any 3 way sli/crossfire cards to get its full potential...

assuming you have money for 3 5870s, you better have money for an i7...

*thinks back to the contest where the lga 1156 i7-860 was the weakest link for $2500*

I was going to get the i7 920 (still possible to switch possibly) but I really wanted to stick with AMD and give them some business

 

[yannifb]

You guys realize that GPU scaling with AM3 vs 1366 is extremely close? There was some bench's showing exactly the same (+ or - a few frames) perf. b/w a 955 and i7 920 with dual 5870's. Tri 5870's should scale close on both as well.

One minute, ill post the benches in a sec.

 

[werxen]

You guys realize that GPU scaling with AM3 vs 1366 is extremely close? There was some bench's showing exactly the same (+ or - a few frames) perf. b/w a 955 and i7 920 with dual 5870's. Tri 5870's should scale close on both as well.

One minute, ill post the benches in a sec.

Agreed. There was even benchmarks between 16x and 8x. The difference was like 5 fps... The only time you will notice FPS drops in PCiE is when you hit 4x and even then it still performs. You do not "need" an i5 or and i7 for anything.

 

[yannifb]

http://www.legionhardware.com/document.php?id=869&p=12

Here it is, well at least the 5970 one which should be close to dual 5870 scaling. I'll search some more for that xfire one.

 

[ubernoobie]

http://www.legionhardware.com/document.php?id=869&p=12

Nice find

 

[andy5174]

andy5174 wrote :

2. Absolutely. You need at least an i5-750 for HD5870 in 2/3-way CF.

LOL

LOL indeed. An i5-750 would be bottlenecked cause of the 16 pci-e lanes.

You need an LGA 1366 for any 3 way sli/crossfire cards to get its full potential...

assuming you have money for 3 5870s, you better have money for an i7...

*thinks back to the contest where the lga 1156 i7-860 was the weakest link for $2500*

Do some research in TOM and Anandtech article and you will realize the difference between 1366 and 1156 is minimal.

http://www.tomshardware.com/reviews/p55-crossfire-nf200,2537.html

p.s. Even 10% difference means 4~5FPS under 1920x1200.

 

[werxen]

Do some research in TOM and Anandtech article and you will realize the difference between 1366 and 1156 is minimal.

http://www.tomshardware.com/reviews/p55-crossfire-nf200,2537.html

http://media.bestofmicro.com/D/7/236347/original/image004.png

http://media.bestofmicro.com/D/8/236348/original/image005.png

p.s. Even 10% difference means 4~5FPS under 1920x1200.

Was looking for those benchmarks to support my claim. Thanks.

 

[Raidur]

http://www.legionhardware.com/document.php?id=869&p=12

Here it is, well at least the 5970 one which should be close to dual 5870 scaling. I'll search some more for that xfire one.

We need to find phenom II 5970 benchmarks like that with resolutions we all actually use. CPU matters less and less when you get the reso that high.

 

[yannifb]

The results shouldn't change too much (and by this i mean the FPS difference b/w the two cpus) from 1920 x 1080. If the OP bought 3 5870s and won't even play at resolutions like that, then.... wtf.

 

[Raidur]

Hehe yeah, hell 3 5870s is overkill even at 25x16.

 

[andy5174]

Hehe yeah, hell 3 5870s is overkill even at 25x16.

Not for rich dudes who have 3 monitors for eyefinity. :lol:

 

[microterf]

Ok. I have a 30" 3008wfp and 2 26" Viewsonics, tried them in eyefinity, but not really impressed. MOre set for 2560*1600 with all settings maxed. I think I'm going to try the eyefinity with FSX and Xplane 9 (those are probably the only games that I'll use it for) As far as overkill, one you turn in 8xAA in Crysis and FArcry, it still brings those 3 cards down to their knees

 

[Cryslayer80]

1. Yes and 3.8GHz in most cases.
2. Absolutely. You need at least an i5-750 for HD5870 in 2/3-way CF.

Arrgh...

 

[Atranox]

1. Yes and 3.8GHz in most cases.
2. Absolutely. You need at least an i5-750 for HD5870 in 2/3-way CF.

1. No. For the C2 - yes. For the C3, absolutely not.

2. No. Both a 955 and an i5 will bottleneck a 5870 tri-fire pretty equally. When OCed, an i5 is at most perhaps a little better when it comes to gaming. Any minor advantage that an i5 has over a 955 is offset by Crossfire scaling on a 1156 as compared to an AM3. They'll be pretty identical in performance I would think. For tri-fire, I would think anything on the 1366 platform would be much more optimal - but neither a good AM3 or 1156 processor would be too bad.

I never understood the purpose of spreading incorrect information just to push for your favorite brands or whatnot.

 

[Raidur]

He was talking about 24/7 on air which 3.8 sounds about right. Unless you don't mind the extra heat I guess... I do.

As far as needing i5, id say it'd be a smarter move than phenom ii but without proper data its hard to tell how big the difference would be. After overclocking id see i5 taking that setup a bit further than phenom ii. Not a whole lot but definitely more than 'about even'.

 

[andy5174]

Arrgh...
http://img708.imageshack.us/img708/3778/54661921.jpg

This is what AMD fanboys normally do, especially Cryslayer80.

You will see him facepalming others as long as they said AMD is worse which is the case right now.

Admit it that AMD is not superior anymore as it was in 2003~2005.

 

[yannifb]

-.-

 

[ionut19]

I would go with i7 not i5 because it gives more lains(pci express 16x 8x 8x or 16x 16x 4x) to the pci express slots and you need them in you want to put 3 cards there. The i5 platform don't give you that many. And as for gaming, i would say i7 is a little faster then any amd but not by much.(that's in games) PS: i haven't researched how good does your CPU do with 3 PCi slots. My post is based on what i read on the forums and many reviews about i7-i5 so far.

As for overclocking your current CPU i say it is ok for 24/7, anyway i don't think you will use it for more then 2-3 years so..

Ad an SSD to your PC and you will have a great machine there.

 

[Cryslayer80]

This is what AMD fanboys normally do, especially Cryslayer80.

You will see him facepalming others as long as they said AMD is worse which is the case right now.

Admit it that AMD is not superior anymore as it was in 2003~2005.

Wanna Godzilla facepalm? Sigh... First, I am not an AMD fanboy, I am anti-Intel and objective in most situations (I can already see this bolded in a quote with a big rofl smiley indicating someone's stupidness). Second, this is what Intel fanboys do more often, but I just need to be "in" by copying them. I will never facepalm a person who says I7 975 is stronger on stock than PII, but will facepalm a statement that I7 975 is the fastest performing PC processor and that it's "just a fact" when actually a similarly clocked 920 delivers the same results for $800 less.

And I have nothing to admit, it is a fact that because people's mass stupidness Intel is very much ahead of AMD in technology (though not in performance) and mobile computers.

 

[noob2222]

Do some research in TOM and Anandtech article and you will realize the difference between 1366 and 1156 is minimal.

http://www.tomshardware.com/reviews/p55-crossfire-nf200,2537.html

http://media.bestofmicro.com/D/7/236347/original/image004.png

http://media.bestofmicro.com/D/8/236348/original/image005.png

p.s. Even 10% difference means 4~5FPS under 1920x1200.

LOL, read his setup and insert foot. 3x 5870, means look at the blue bars. x58 = 70.7, p55 = 35.8 .... 50% = minimal ...

There was a post on the graphics forums a month or 2 back showing scaling performance of i7 vs am3. The I7 capped where the AM3 kept going up and actually getting ahead of the I7 in some cases (above 4 ghz if i recall)