Crossfire 290x cooling (universal blocks)

[Deorcn]

Greetings overclockers! I have just joined the forum and would like to ask a couple of questions.

 

1.) I've recently gotten hold of two 290x and am currently running them on universal waterblocks (EK-Supremacy). Are heatsinks on the VRAM/VRM/MOSFET absolutely necessary? There has been several citations on various sites claiming that they should be fine naked as they are designed to function normally @ ~100C. Should I really be concerned?

 

2.) Are there any other ways to help keep the VRAM/VRM/MOSFET cool? 

 

3.) The two 290x are reference models (1x sapphire 1x powercolor); does anyone know the ideal OC + Voltage combination (keeping in mind the maintenance of safe temps)? 

 

4.) Will operating on PCI-E 2.0 x8 bottleneck the 290x or does the card not saturate the bandwidth at all?

 

5.) Will my PSU be sufficient for doing an OC-ed 3-way 290x crossfire setup?

 

6.) In the scenario of a 3-way crossfire, would the fx-8350 be enough, or will I need the fx-9590? or even something from intel's LGA2011v3 series?

 

7.) Can two 290x support a triple 4k setup?

 

 

Current Build:

CPU: AMD FX-8350

MOBO: ASUS Sabertooth 990FX R2.0

GPU: AMD Radeon R9 290x  (x2)

RAM: 16GB Apacer DDR3 1600 

PSU: Corsair HX1000i

SSD: Kingston HyperX 3K 120GB

HDD: 2TB Western Digital Green

Cooling: Custom Loop (EK Supremacy VGA & CPU)

Casing: CM Storm Trooper

Monitor: Samsung UHD 28" 4K

Speakers: Audioengine 5+

[Pteroduck]

1) Are those waterblocks full blocks that cover the whole PCB or just the GPU chip? If it's the whole board, you should be fine, otherwise I would get the heatsinks just in case. Doesn't hurt to be safe. AMD r9 series are built to be hot but I wouldn't feel safe running it that hot 24/7 because it would degrade the card alot.

2) Decent air flow would help here along with, generally speaking(assuming you wont keep it in a corner to build up heat) you wouldnt need to worry about it too much unless you plan on mining 24/7.

4) SLI/Crossfire run 8x 8x most of the time. You run 16x when you have one card in for most motherboards. They go 8x 8x(split the bandwidth) when you double it. In terms of saturation, the pci-e 2.0 is far more than enough for the card.

5) Yes, the power supply is enough for two way. R9 CF would require a 1kW so I say no. Make sure it's platinum or some decent rating atleast. I believe I read somewhere that R9 290 x3 requires a 1300w. I would not recommend using three cards, instead, buy the best/highest card and stay single. Keeps the headaches away. It's just my opinion though, some people say CF/SLI, some don't. I believe it's at your discretion to use either or.

6) Your CPU would probably be the last thing bottle necking your system. You don't need to be worrying about intel's premium never the less. If you  could, maybe you can try the 4690k as I believe the 990fx line is dead at the moment(correct me if im wrong)

7) Yep.

 

[Waco]

VRMs will cook without good cooling. I wouldn't use universal blocks on any GPU these days.