CrossFire r9 280 Power Question

Hello,

I recently purchased a second MSI r9 280 and was wondering if my Tt 750w toughpower gold will be able to power both cards. I have an i7 4790k (auto OC 4.4ghz), msi gaming 7, 16gb ddr3 1600 ram, a dvd drive, an ssd, an HD, a cpu cooler with 1 fan, and 4 other fans. I do not run my LED lights. And I can always disconnect the dvd drive (after making a bootable usb or something in case windows error). I use a mouse and keyboard and a wired 360 controller at times. There are plenty of empty plugs on my power supply.

The min req for crossfire looks like 750, but I'm wondering if I'll run into errors overclocking? Am I forced to buy a new psu? I've looked at other threads and some say it's ok , others say 850 or higher. but I have a feeling some folks just say 850 just to say 850.

Is there a way to test my systems power consumption?

750W is really the required wattage for CrossFire R9 280. But if you decide to go on 850W then it'll be a good idea for breathing room :)

This review should shine some light on your question.

MSI Radeon R9 280 3GB Twin Frozr Gaming OC in CrossFire OCed Review - Power Consumption Testing

numbers are nearing the top, with a little over 800 watts being seen at load. This is quite high, and for something like this we'd really recommend that you're purchasing a quality PSU around the 1000 watts mark to make sure you're completely covered.

Read more at MSI Radeon R9 280 3GB Twin Frozr Gaming OC in CrossFire OCed Review - Power Consumption Testing

So to answer your question.
Can you get by with your power supply; maybe.
You won't know until you try.

If it was my computer it would get a higher wattage power supply.
Once the money has been spent on the rest of the system like yours it's no time to be skimpy on power.

Just my opinion.

Note:
Running two of those cards the case air circulation must be the best you can make it.

Layback Bear said:

This review should shine some light on your question.

MSI Radeon R9 280 3GB Twin Frozr Gaming OC in CrossFire OCed Review - Power Consumption Testing

numbers are nearing the top, with a little over 800 watts being seen at load. This is quite high, and for something like this we'd really recommend that you're purchasing a quality PSU around the 1000 watts mark to make sure you're completely covered.

Read more at MSI Radeon R9 280 3GB Twin Frozr Gaming OC in CrossFire OCed Review - Power Consumption Testing

So to answer your question.
Can you get by with your power supply; maybe.
You won't know until you try.

If it was my computer it would get a higher wattage power supply.
Once the money has been spent on the rest of the system like yours it's no time to be skimpy on power.

Just my opinion.

Note:
Running two of those cards the case air circulation must be the best you can make it.

Cool. Looks like minimum is 850w but I should get a 1000w. Is there a power supply that you could recommend for i7 4790k and z97 board? Corsair RM1000?

I use Corsair AX and AXi series power supplies. Never had a problem with them.

Layback Bear said:

This review should shine some light on your question.

Note:
Running two of those cards the case air circulation must be the best you can make it.

I have a large 200mm fan (corsair oem) on the side panel, but it's got mounting points for more smaller fans IF I remove the 200mm fan. The 200mm fan blows directly over my video card(s). I have an intake fan at the bottom next to the PSU. 2 intake fans on the front. 1 exhaust out the back. And an open hole / 120mm cpu cooler with fan at the top. I'm fairly certain the fan exhausts too. I'll be switching soon to a 240mm rad with dual fans (corsair h100i) that will both be exhaust fans (I'm assuming) on top of the rad. Do you think that's enough air flow?? Or maybe I should replace the side fan with a bunch of small fans?? I guess I could always upgrade the parts and then check/monitor temps and such under load.

PS. Going with the evga 1300 p2 gold. Fits in my budget and gets some solid reviews. ax etc, kinda sits out side of my price range.

When i ran Crossfire 7970's I had a AX850 and a hefty 4.8 Ghz on my AMD 8350 at the time

Now i run Intel which is a lot lower in power so i would say you should be safe given AMD uses much more power

Still getting a little more power doesn't hurt and insures stability

Well monitoring you case temps is always a good just like monitoring all temps is

Small suggestion.
In my case the stock Corsair 200mm fan blows very little air. It can't even make a candle flicker. I think that Noctua and Phanteks have quality replacements if you can find them.

With the H100 exhausting out the top.
Two front fans intake
Bottom fan intake
Back fan exhaust
Side fan intake
You should be close to a positive pressure case.

I try to not only have more intake than exhaust. I also try to control the path the air takes.
I block all holes that don't have a fan mounted in them. I use the foam that comes with the video card and power supply packaging. Doing so would force the air to exhaust out the rear fan and through the radiator. I will see if I can find a picture.

I will have to boot my other computer where the pictures are.

Well this is the best I can do for a picture.

Notice the back, just behind the water cylinder that every hole except where the fan is is covered. Except for the small hole at the back of the video card and the outlet for the motherboard fan exhaust. 99% of incoming air must exhaust out through the top radiator.
On the top their is one fan location that is blocked and on the bottom their is also one fan location that is blocked. In the front their is one fan location blocked because it is where my pumps are.

To make a long story shorter.
I control exactly where the air intakes and exactly where it exhaust and that creates a flow patter of the air movement through the case.
Air moving through a case and not doing its job makes no sense to me.

This also worked well even before I water cooled my video card.

Solarstarshines said:

When i ran Crossfire 7970's I had a AX850 and a hefty 4.8 Ghz on my AMD 8350 at the time

Now i run Intel which is a lot lower in power so i would say you should be safe given AMD uses much more power

Still getting a little more power doesn't hurt and insures stability

Ya my buddy I work with told me about nvidea lower power consumption. I went with an intel chip (i7) so there's less power to power that than say an amd CPU. But for graphics cards this was my first time going with an amd GPU. I'm very pleased with the results and he bang for the buck ... But 250wats per card??!! That I'm not so happy about.

Layback Bear said:

Well monitoring you case temps is always a good just like monitoring all temps is

Small suggestion.
In my case the stock Corsair 200mm fan blows very little air. It can't even make a candle flicker. I think that Noctua and Phanteks have quality replacements if you can find them.

With the H100 exhausting out the top.
Two front fans intake
Bottom fan intake
Back fan exhaust
Side fan intake
You should be close to a positive pressure case.

I try to not only have more intake than exhaust. I also try to control the path the air takes.
I block all holes that don't have a fan mounted in them. I use the foam that comes with the video card and power supply packaging. Doing so would force the air to exhaust out the rear fan and through the radiator. I will see if I can find a picture.

I will have to boot my other computer where the pictures are.

Well this is the best I can do for a picture.

Notice the back, just behind the water cylinder that every hole except where the fan is is covered. Except for the small hole at the back of the video card and the outlet for the motherboard fan exhaust. 99% of incoming air must exhaust out through the top radiator.
On the top their is one fan location that is blocked and on the bottom their is also one fan location that is blocked. In the front their is one fan location blocked because it is where my pumps are.

To make a long story shorter.
I control exactly where the air intakes and exactly where it exhaust and that creates a flow patter of the air movement through the case.
Air moving through a case and not doing its job makes no sense to me.

This also worked well even before I water cooled my video card.

Hmmmmm ok. Lots to think about. I have my new power supply.



And my 2nd graphic card and ram (not new just RMA replacement) are still on there way. :-/ So I'll have to find some stuff to block a hole at the top of the front of the case above the two intake fans around the DVD drive. But I think that's a good idea. I have the foam from the old graphics card in the garage but if not, new one is on it's way. I'm thinking about waiting to do that stuff for when I get the corsair bigger rad for up top. Plus I might yank the DVD drive and just block that whole area. But thanks for the tips. Really looking fwd to digging into her again. Several upgrades coming to my rig now, and the rad eventually. That will be the last thing ... (Famous last words?) ...