Intel Haswell DDR3 Memory Performance Impact On Graphics

[phoronix]

Phoronix: Intel Haswell DDR3 Memory Performance Impact On Graphics

For starting a new week of Linux benchmarking at Phoronix, some more results to push along Monday morning are performance test results looking at Intel's Haswell Linux graphics performance when manipulating the DDR3 memory frequencies. These results show the impact of Intel Haswell graphics on Linux when running the system memory at DDR3-800, DDR3-1066, DDR3-1333, and DDR3-1600 MHz frequencies... The performance difference of the latest-generation Intel graphics may surprise you.

http://www.phoronix.com/vr.php?view=19244

[mendieta]

I saw a similar trend with memory, though it seemed to have plateau'd in my tests beyong 1600. It would be nice to play with the clock for Haswell. It actually gives me a lot less, not more, performance, as I increase the max freq (even with kernel 3.12, though I havent tried mesa 10)

[MWisBest]

I'm honestly not surprised, you should see what a difference just having dual-channel memory makes on its own with these system-RAM-using GPUs!

[edoantonioco]

Great job. I am still waiting for a catalyst vs radeon free driver.

[devius]

Of course we don't know the memory timings, which also have a small impact in performance. Maybe the SPD settings for DDR3-1066 have worse timings than DD3-800, thus negating any positive effect the faster clock would bring. Or, maybe it's always something like 9-9-9-24 for all clock speeds, except DDR3-800 where it's 7-7-7-21, which could also explain it.

[guido12]

Of course we don't know the memory timings, which also have a small impact in performance. Maybe the SPD settings for DDR3-1066 have worse timings than DD3-800, thus negating any positive effect the faster clock would bring. Or, maybe it's always something like 9-9-9-24 for all clock speeds, except DDR3-800 where it's 7-7-7-21, which could also explain it.

If you want a more detailed analysis with timings then you could read the tests AnanTech did: http://www.anandtech.com/show/7364/m...ing-on-haswell

It may not be under Linux but I assume the results are relevant to all Haswell systems. Also, there are more than just GPU tests.

[devius]

If you want a more detailed analysis with timings then you could read the tests AnanTech did

Yeah, I had already read that article. Very interesting, but it doesn't go as low as DDR3-800, or even 1066 which is where the issues are here.

[guido12]

Yeah, I had already read that article. Very interesting, but it doesn't go as low as DDR3-800, or even 1066 which is where the issues are here.

Oh, sorry. I should have read your post more thoroughly.