Originally Posted by wildjjbug
I'm getting alittle confused now..
Will my 6670 crossfire with my 5400k? Because I'm about to accept my order.
There aren't many choices on my local market.
Yes an HD6670 will crossfire with a 5400K, however, the results are apt to be worse than just running the HD6670 as a discrete GPU.
The reason for this, is that crossfire splits workload either frame-by-frame (every other frame) or split-screen, and whichever method is being employed for crossfire creates a 50/50 split in workload between the 2 GPUs. The result is that, the best theoretical performance possible in crossfire is twice the performance of the most significant bottleneck present. This is why AMD has those charts that push consumers toward pairing cards of similar capability, so that hardware capacity isn't simply thrown out the window due to a bad pairing.
The HD7540D has 192 shader cores, 12 texture mapping units, 4 render output units, and an available memory bandwidth of ~15GB/s on the AMD memory controller.
The HD6670 has 480 shader cores, 24 texture mapping units, 8 render output units, and an available memory bandwidth of ~25GB/s OR 64GB/s if GDDR5.
In order for the HD6670 to crossfire with the HD7540D, it is effectively "throttled"
back to match the workload of the HD7540D. Given what you know from the numbers above, would you rather have the HD7540D's performance multiplied by 2 (peak best case scenario performance), and then taking all of the tradeoffs of crossfire (scaling losses, frame delivery timing issues, driver/game support often lacking, etc etc) Or just use the HD6670 in a discrete manner and enjoy what is likely to be better performance in 99% of scenarios?
An Ivy or Haswell Pentium chip paired with a discrete HD6670 would out-perform an A6-5400k+HD6670 in every measurable metric of general consumer computing/gaming. The A4 and A6 series are garbage chips in their price class, outpaced substantially by the Pentium series in compute performance. The only case where the A4/A6 have a minor edge is in comparisons that do not involve any discrete GPU at all (not the case here) or where special instructions are needed (highly unlikely that these chips are chosen by people who need a heavy lifter chip for encryption).
I'd like to see a budget class single module richland chip with ultra-high clocks from AMD with the 8570D (or better) on it. Give it a 100W envelope and let er rip at 5ghz. Price it at $80. Serious competition for the Pentium for budget sensitive enthusiasts.
You were on the right track with the Pentium chip originally for an ultra budget build involving a pre-existing HD6670. Check pricing at the time of the build for an entry level 1150 socket board and the G3220 instead as they are usually priced very similar to the Ivy options. If you can do the Haswell for about the same price may as well.Edited by mdocod - 11/24/13 at 12:47am