Now let’s take the block apart:
DSC_1616The main cooling engine itself is on a separate plate to the one that the large front aluminum plate attaches to.  This means that the VRM and memory won’t benefit from it, but also that the core doesn’t really get warmed up by them either.  While we can see discoloration of the plated copper, we don’t really see any flaking.  As mentioned this is the same core as used in the R9-290 so we expect to see similar thermal performance but also similar restriction.

Flow Rate Testing

If you don’t know how to read a pressure/flow plot then check out our guide.  Testing was done by hooking up the block under test to a water faucet/tap and varying flow through it.  Flow was measured using a 5GPM King Instruments Rotameter, and pressure across the block was measured using a Dwyer differential manometer.  A Koolance CPU-380 block is also used here as a reference point:

980restriction

It can be seen that all but two of the blocks have similarly low restriction.  Alphacool’s block has the worst restriction by far.  At 1GPM it has over 4.5PSI of back pressure.  This is really really high.  In other words adding this block in your loop *will* effect your flow rate negatively.  The cooling performance of your radiators might suffer and the cooling performance of your CPU block may also suffer.  The money you might save buying this may be necessary to apply towards a second pump in order to run it at a decent flow rate.

Onwards to thermal performance!

3 COMMENTS

  1. I have a pump with ~600l/h and ~3m head pressure. I have 240 and 360mm radiators and Heatkiller III Acetal on my 4670k. Will i be ok with this GPX block? Only Alphacool has block for my card, so i’m worried if my pump is enough.

  2. […] waterblock for the core and what is essentially giant heatsinks for the VRM and VRAM. Review here. Alphacool NexXxos GPX GTX 980 M02 with Backplate Review – ExtremeRigs.net 2. EK Thermosphere, which is a universal block. You'll need to modify the stock G80 mounting […]

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