4870X2 and 4870 1GB TRI-FIRE PSU Limits??

[Face2Face]

Hello people,

Thinking about going the Tri-fire route. I have an Asrock 880G extreme with 3 physical 16 x slots. the first slots turn into 8x slots when two cards are installed in crossfire. The third slot is 4x and I don't think is affected by the settings of the other two. Would running a 4870X2 and 4870 1gb @ 8X make a large impact? Or should I say screw Tri-fire and stick with my 4870x2 and use an nvidia card for PhysX. Also would a Corsair 750 Watt with a 60amp 12v rail be good enough for a Tri-fire setup. I have the hardware below plus two optical drives and 8 120mm fans. I do plan on getting my Phenom II to the 3.8-4.0 Ghz range if possible.

Let guys, thanks in advance

 

[CitanUzuki]

I know this is not even close to a complete answer to the many questions that you are asking, but im pretty sure alienbabeltech had a mix crossfire write up you might want to check out.

 

[lavaheadache]

I ran the same setup on a 16x -8x setup with zero issues. The second card(4870)in the 8x slot was hampered by less than 2 percent. I would do it. Tri fire scaling is damn excellent too!

 

[TurtleCrusher]

Is your 4870x2 the 1GB variant? I'd be more worried of a 512mb buffer being the bottleneck.

 

[f4phantom2500]

Is your 4870x2 the 1GB variant? I'd be more worried of a 512mb buffer being the bottleneck.

I'm also curious as to what kind of detriment you would see when comparing a 4870 TriFire setup utilizing 512MB vs 1GB cards at 1920x1080.

Having said that, if your 4870X2 does have 512MB per chip, I think you would be better served with a 4870 512MB as your third card. Someone correct me if I'm wrong but wouldn't CrossFire run the third card at 512MB regardless if the X2 is 512MB per GPU?

 

[lavaheadache]

there in no such card as a 1gig 4870x2

 

[f4phantom2500]

there in no such card as a 1gig 4870x2

I believe we were thinking of the 4850X2 1GB. Thanks for the correction.

 

[TurtleCrusher]

there in no such card as a 1gig 4870x2

My bad. I thought there was. I was looking at the 4850x2 a long time ago. Oops.

 

[Face2Face]

The 4870X2 would be 1gb per GPU- 2gb total. That's the only one they made that I am aware of. The 4870 I would pair it up with would aslo be a 1GB card. Do you think a 750 watt corsair would be straight with all the things I have in my system?? My first Corsair PSU was A POS--It would always shutdown my PC when my old GTX 280 was getting Nasty on it. I have my RMA replacment coming in on this coming Monday.

 

[apoppin]

Hello people,

Thinking about going the Tri-fire route. I have an Asrock 880G extreme with 3 physical 16 x slots. the first slots turn into 8x slots when two cards are installed in crossfire. The third slot is 4x and I don't think is affected by the settings of the other two. Would running a 4870X2 and 4870 1gb @ 8X make a large impact? Or should I say screw Tri-fire and stick with my 4870x2 and use an nvidia card for PhysX. Also would a Corsair 750 Watt with a 60amp 12v rail be good enough for a Tri-fire setup. I have the hardware below plus two optical drives and 8 120mm fans. I do plan on getting my Phenom II to the 3.8-4.0 Ghz range if possible.

Let guys, thanks in advance

i tested HD 4870-X3 TriFire quite extensively at 19x12 and 16x10. The X2 is quite an impressive card that trades blows with HD 5870 in DX10.1 games if you don't mind the noise and power draw. Adding the HD 4870 as a third linked adapter does add a nice performance boost to many games.

i also ran HD 4870-1GB + HD 4870-X2-2GB on a 600 W PSU for my Cooler Master Silent Pro 600 review and it was sufficient even though the total power draw from the wall would occasionally blip 600W with an overclocked Core i7 @ 3.8 GHz.

i would not recommend an even very stable 600W PSU for HD 4870-X3 TriFire as described above, however. 750W would be perfect. Go for it if your Corsair is stable.

 

[evolucion8]

i tested HD 4870-X3 TriFire quite extensively at 19x12 and 16x10. The X2 is quite an impressive card that trades blows with HD 5870 in DX10.1 games if you don't mind the noise and power draw. Adding the HD 4870 as a third linked adapter does add a nice performance boost to many games.

i also ran HD 4870-1GB + HD 4870-X2-2GB on a 600 W PSU for my Cooler Master Silent Pro 600 review and it was sufficient even though the total power draw from the wall would occasionally blip 600W with an overclocked Core i7 @ 3.8 GHz.

i would not recommend an even very stable 600W PSU for HD 4870-X3 TriFire as described above, however. 750W would be perfect. Go for it if your Corsair is stable.

You got lucky, I had thermal and power issues with my current power supply with only two HD 4870 1GB in Crossfire, the power supply gets very hot and would shut down the system. And for sure, an i7 overclocked to the same 3.80GHz as my system will suck more power during peak load. I switched some peripherals to other 12V connections and now works fine as far as the case is open. I think my X-Fi is blocking the air flow to the power supply. During heavy load with Furmark, I can see the power leds of my Sapphire card fading slightly like if the power supply being pushed to the limits.

The 4870X2 would be 1gb per GPU- 2gb total. That's the only one they made that I am aware of. The 4870 I would pair it up with would aslo be a 1GB card. Do you think a 750 watt corsair would be straight with all the things I have in my system?? My first Corsair PSU was A POS--It would always shutdown my PC when my old GTX 280 was getting Nasty on it. I have my RMA replacment coming in on this coming Monday.

Corsair 750W should be enough for a heavily overclocked Quad Core and two HD 4870 in Crossfire.

 

[Face2Face]

I know the Corsair 750 watt is a little underrated-- more like 800-850 watts looking at comparable 750 watt PSU's. I had a lot of issues with my PSU overheating as well. I turned it upside down in my case so I would get more air that way. Stock setup in my case pulls air from under the case and that was causing problems. I just have to find a 48701gb for a good price. I got my 4870X2 for a $180.00 it's a OEM card. Thanks for all of your help guys.


Also would 8x pcie 2.0 slot hurt the x2's performance??

 

[evolucion8]

I know the Corsair 750 watt is a little underrated-- more like 800-850 watts looking at comparable 750 watt PSU's. I had a lot of issues with my PSU overheating as well. I turned it upside down in my case so I would get more air that way. Stock setup in my case pulls air from under the case and that was causing problems. I just have to find a 48701gb for a good price. I got my 4870X2 for a $180.00 it's a OEM card. Thanks for all of your help guys.

So in your PC case, your power supply goes at the bottom, but I have a question. When you fixed your overheating issue turning the power supply upside down, is the fan currently looking up or down?

 

[apoppin]

You got lucky, I had thermal and power issues with my current power supply with only two HD 4870 1GB in Crossfire, the power supply gets very hot and would shut down the system. And for sure, an i7 overclocked to the same 3.80GHz as my system will suck more power during peak load. I switched some peripherals to other 12V connections and now works fine as far as the case is open. I think my X-Fi is blocking the air flow to the power supply. During heavy load with Furmark, I can see the power leds of my Sapphire card fading slightly like if the power supply being pushed to the limits.



Corsair 750W should be enough for a heavily overclocked Quad Core and two HD 4870 in Crossfire.

No, i think you are unlucky or else your 700W OCZ is unstable - they *DO* exhibit a lot of ripple when they get near their rated output; i also have a OCZ 850W PSU.

My HD 4870-X3 TriFire peaked with a max power draw at 600W from the wall as a "blip" as measured by Kill-A-Watt. A very stable 750W PSU (not yours) should be able to handle it; what my point of the review was that CM had really underspec'ced their Silent Pro 600W as a kind of reaction to overspeccing them in the past.

You should NEVER have to take your side panel off. You need more fans or a better air flow. It took me 5 case fans in my Gladiator 600 to keep my GTX 480 from roasting my other HW. Now i am using Thermaltake Element G oversized mid-tower with 3 x 240MM fans + 1 x 140 MM fan with great results.

As a tip for you specifically, flip your PSU upside down (if it is at the bottom of your case) and it will be completely separated from the airflow of the case; it will draw cool air in from below your case and spit it out its grill. Then you can close your case and keep the noise down.
:thumbsup:

 

[evolucion8]

Thanks, the power supply is at the bottom of the case with the fan in the upside position. Will try it with the fan looking down to see if it may help, but that may stagnate the air right? will try it in a moment.

 

[apoppin]

Thanks, the power supply is at the bottom of the case with the fan in the upside position. Will try it with the fan looking down to see if it may help, but that may stagnate the air right? will try it in a moment.

You're welcome. The way you had it, it is sucking hot air from just below the graphics card and sending it through the PSU.

If air somehow stagnates with the PSU in the other position, make *sure* there is nothing blocking the bottom of your case and clean the dust filters as needed. You should have 1/4 to 1/2 inch of clearance below your case where the air is relatively cool. i live in a very hot place for the Summer.

EDIT: When you say "stagnate the air", you are now taking your PSU's fan out of the case's air flow when you turn it over. The PSU drops out of the case's airflow completely. How many case fans do you have?

 

[Face2Face]

My PSU was fan facing down taking air out at the bottom of the case. I had multiple shut downs playing games with a GTX 280. When I turned the PSU fan up pulling air from within the case the problem still persisted but not as often. So the PSU fan stopped spinning on the unit so I sent it back for RMA. The PSU was a lemon I think from the get go. I have really good air flow in my case 8 120mm case fans in total including the two on my HSF. Hope this new PSU works with out an issue. I will find out this coming monday. I also have a side panel fan blowing air right above the PSU to help bring in colder air.

 

[evolucion8]

Definitively your Power Supply was a lemon, hopefully your replacement should work fine.

Appoppin: My case has three 120mm fans and one 190mm fan at the top, (Antec Nine Hundred V1)

 

[apoppin]

Definitively your Power Supply was a lemon, hopefully your replacement should work fine.

Appoppin: My case has three 120mm fans and one 190mm fan at the top, (Antec Nine Hundred V1)

Agreed on the Gh6 PSU. It depends on the case and the airflow whether to turn your PSU up or down.

You have a nice airflow in a good case Ev8. i am shocked that you need to leave the case panel off. Have you had time to note any stability differences with your PSU now turned over?

Perhaps it is just not meeting its spec

 

[evolucion8]

I tried to turn the power supply upside down, but there's no even half a centimeter of space between the power supply and the case bottom which will impair severely the air flow. So I didn't try the tests.

 

[apoppin]

I tried to turn the power supply upside down, but there's no even half a centimeter of space between the power supply and the case bottom which will impair severely the air flow. So I didn't try the tests.

Your case is different than my cases.

In both of my Cooler Master cases (Gladiator 600 and Elite 430 Black) there is a grille on the bottom of the case so that the air gets sucked in from underneath the case; there are dust filters supplied to keep the PSU from getting clogged with dust.

In my Thermaltake Element G (oversized) mid tower, there is a little space beneath the PSU and the case's bottom *plus* a grill cut into the floor so the air can be drawn into the PSU from beneath the case. i love that case; it has 4 huge fans including a 240 MM side case fan that come with it with variable speed adjustment
(the same knob adjusts the light show also )

 

[evolucion8]

It doesn't have any grill at all, , is totally sealed. I might use a driller and do it myself once I return from Germany for Annual Training.