• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

FRONTPAGE AMD R9 295x2 Video Card Review

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.
Wow, this is insane.

Do dual GPU vid cards at least end up using less power than two, discrete
GPU's of the same type (at idle and load)? Or more?

888 Watts power usage = 8 amps at the wall socket? What happens if you
only have a 6 amp circuit breaker?

At the last LAN party I went to, there were power outages, this despite
the fact the host had upgraded his circuit breakers specifically for this
LAN party.

This GPU has a 500W TDP. So it'll use double the power of one 290X.

6 amp breaker? Get a bigger breaker, can't do much to cut down power draw on dual GPUs.

"I bet a lot of people are curious as to how the Asetek built 120 mm AIO worked on getting rid of up to 500 watts of heat"

Not really. Because it is only cooling the 2 cores of the card, and not the whole card. So I would guess that it is more like 200-250 watts that it is cooling, which given the temps under load seems about right. Sorry, but I just had to point that one out, it's the smart *** in me :D

Probably more like 400W, actually. vRAM and VRMs are typically passively cooled underneath the heatsink that cools the GPU itself.
Sometimes without any heatsink at all on them. They put out minimal heat compared to the core.

Considering the core(s) is going to be 90+% of the heat, it isnt far off. Think of the video card like you would a cpu and motherboard, the overwhelming majority of the heat and power use is the cpu.

Bingo!
 
Wow, this is insane.

Do dual GPU vid cards at least end up using less power than two, discrete
GPU's of the same type (at idle and load)? Or more?

888 Watts power usage = 8 amps at the wall socket? What happens if you
only have a 6 amp circuit breaker?

At the last LAN party I went to, there were power outages, this despite
the fact the host had upgraded his circuit breakers specifically for this
LAN party.
In the past, AMD's dual GPU on a stick were cut down versions of the card. Some shaders may have been cut off or more typically, the clocks were lowered. As also mentioned in the review, this is their first full fledged flagship that was not cut down to make a dual GPU and in fact, the clocks were raised slightly from reference (to offset the latency of the onboard PLX chip).

6 amp circuit breaker? Who has that in a house?!!! Arent they all ~1500W outside of the washer/dryer/kitchen circuits (in the US)?

He needs better power/circuit management me thinks... knowing the power of the rigs going on each one making sure its under the rating of the circuit. :thup:

Considering the core(s) is going to be 90+% of the heat, it isnt far off. Think of the video card like you would a cpu and motherboard, the overwhelming majority of the heat and power use is the cpu.
Exactly.
 
Last edited:
6 amp circuit breaker? Who has that in a house?!!! Arent they all ~1500W outside of the washer/dryer/kitchen circuits (in the US)?

Yeah, unless he's in a really old building. Last time I checked, each household circuit for all construction since sometime in the 70s must be able to provide 15 amps @ 120V, and at least one circuit in the kitchen must be be able to provide 20 amps @ 120V. If you've got a 6 amp breaker on one of those, something is seriously wrong.

At the last LAN party I went to, there were power outages, this despite the fact the host had upgraded his circuit breakers specifically for this LAN party.

Bigger breakers aren't going to do crap if the wiring can't handle it. First the room needs to have multiple independent circuits, then those need to have sufficient-gauge wire, then you can finally put in bigger breakers :) Also, many single-home breaker boxes can't even do more than 400 amps to start with. Between random household appliances and lights, the fridge in the kitchen, and however many amps the air conditioner is gulping down in a futile attempt to keep that party room from melting, you're not left with enough amps for more a dozen or so people with state-wide blackout-inducing quad-fire setups :) If you're having a LAN party for those systems, you're probably going to have to invest several thousand dollars in electrical upgrades.

Off-topic: Please don't add manual line breaks to your posts :)
 
Last edited:
Yeah, unless he's in a really old building. Last time I checked, each household circuit for all construction since sometime in the 70s must be able to provide 15 amps @ 120V, and at least one circuit in the kitchen must be be able to provide 20 amps @ 120V.

Most circuit boxes have a dual 20amp configuration to make 220/240v available also.
 
nice review. I'm on the fence about getting one and swapping out for me Asus 780. May wait for the Asus 27 screen to arrive and determine if i need another first
 
It looks like one of the GPU cores is getting the already heated water from the other GPU, so both GPU's are on the same loop. Ideally, wouldn't it be better to have each GPU on its own loop?
 
It looks like one of the GPU cores is getting the already heated water from the other GPU, so both GPU's are on the same loop. Ideally, wouldn't it be better to have each GPU on its own loop?

So.... you're getting water that's ~1°C hotter. Whooptie doo.
 
It looks like one of the GPU cores is getting the already heated water from the other GPU, so both GPU's are on the same loop. Ideally, wouldn't it be better to have each GPU on its own loop?

So.... you're getting water that's ~1°C hotter.
In properly radded and properly flowing loops, the temperature difference between the coolest part and warmest is within 1-2C (See martin/skinee labs research on this). During my testing, core temps were about 1-3C apart. ;)

So what brought that up 3 months after you were in the thread last?
 
In properly radded and properly flowing loops, the temperature difference between the coolest part and warmest is within 1-2C (See martin/skinee labs research on this). During my testing, core temps were about 1-3C apart. ;)

So what brought that up 3 months after you were in the thread last?

That was before I read the watercooling stickies. So the separate loops watercooling method isn't really worthwhile?
 
It's worthwhile, sure, but not because of internal temp differences in a loop (if you are still curious, you would be better served starting a thread in the watercooling section).
 
That was before I read the watercooling stickies. So the separate loops watercooling method isn't really worthwhile?

If you read the stickies you should know two things:
- Loop temperature equalizes to +1-2°C at any point in the loop.
- Separate loops are all but useless with today's technology.
 
Wow, this is insane.

Do dual GPU vid cards at least end up using less power than two, discrete
GPU's of the same type (at idle and load)? Or more?

888 Watts power usage = 8 amps at the wall socket? What happens if you
only have a 6 amp circuit breaker?

At the last LAN party I went to, there were power outages, this despite
the fact the host had upgraded his circuit breakers specifically for this
LAN party.

The 8 AMPs could become a issue for many US and perhaps Japanese and other 100-110 V territory because its more difficult to power up a certain line when there is less Volt because it can become hot, thus increasing the risk of fire and other failures. But in EU and other countrys there is a 220 V line at the wall and such a line is able to supply ~2000-4000 W without any sweat and at a very safe level. I got a 10 AMP circuit breaker, over 220V it means it can supply 2200 W, on a single line (or rail, in PC terms). So even 2x 295x2 at once is a easy task to handle but i see no reason to use such a insane overpowered build, guess i rather would spend the money on tea. :D Even a single 295X2 is a crazy monster... i guess i would have to nail down my PC case on a anvil first because i fear it could fly toward my ceilling during gameplay once the 295X2-vesuvius-volcano is properly fired. wink.gif

But indeed... the GPU fight AMD is executing is juicy stuff and Nvidia has never been on such a "contested" spot ever, i do believe. Radeon GPUs nowadays truly are powerful but they may need the right cooling hardware and arnt always easy to tackle. Its a hard beast to tame and it has been that way since GCN has been around the first days. Although im pretty sure Overclockers are having fun with...

Btw: Of course at current time its probably possible to make a 4x 980 GTX quad-SLI setup with about same performance and most important much higher efficiency*, resulting into lower TDP and less heat, so its simply giving horsepower without many drawbacks a "high TDP" setup got. However, the price (2x 295X2 vs. 4x 980 GTX) is probably more or less the same (didnt check current market prices but im sure 295X2 prices will go down). When overclocked even 4x 970 GTX could be able to have almost equal performance but it will be at the cost of lesser efficiency but still higher than 2x 295X2. Although some games are running better on Radeon cards so it wont always keep up with 2x 295X2. But im sure the price tag may be more or less the same in the near future, the dual GPU AMD cards always was dropping a lot as soon as some good alternate option was around.

*2x 295X2 is around 1000 W, 4x 980 GTX around 700 W, 4x 970 GTX @ OC probably around 800 W (a bit less efficient than a 980 GTX at comparable performance). So it could be more power efficient at the same or smaller (970 GTX @ OC) price tag.
This GPU has a 500W TDP. So it'll use double the power of one 290X.
The TDP is a estimated thing, its the possible TDP under average gaming load or something like that (manufacturers may have different terms/conditions for measuring it). In theory it could be higher or lower than that, but in realistic terms on a game using around 90% average load, i think the 500 W is more or less correct. Its still not the max load, and a circuit breaker may react sensitive to "spikes", spikes above 500 W are totaly possible. So a circruit breaker need a good margin above the TDP values, else i would consider it unsafe.

6 amp breaker? Get a bigger breaker, ! [...]
Its not always safe just to "switch out" a power breaker/fuse because some cable installations are that old that it could provide serious risk of fire and other failures. So if the cable installations are way to dated it may need a complete overhaul and thats not free. Better be safe than sorry... a power breaker/fuse need to be adapted to the current situation, and cant just freely be exchanged with a bigger one. On top of that, the "up to date" installations doesnt provide a lose and exchangeable power breaker/fuse, its fully implemented into the power relay, although in US most of the stuff is pretty "dated" and may be lose.
 
Last edited:
Back