Intel RC6 Support On The Sandy Bridge Desktop

[phoronix]

Phoronix: Intel RC6 Support On The Sandy Bridge Desktop

While RC6 support remains off-by-default as Intel developers are faced by RC6-related bugs affecting a small minority of Sandy Bridge users, this power-savings feature is not limited to only Intel mobile graphics. As discovered at Phoronix, RC6 can manage to boost the graphics performance beyond just extending your battery life. The RC6 performance boost is also quite visible on Intel Sandy Bridge desktop hardware too.

http://www.phoronix.com/vr.php?view=17028

[darkbasic]

Which detail level did you test doom3 with? I hope not low because my 6600gt was able to run it at 60 fps @1280x1024 with Ultra quality setting

[schmidtbag]

holy crap seriously, do the intel graphics chips have a bottomless pit of spare performance because it seems like every release has had a noticeable performance improvement. all they really need to focus on at this point is improving high resolution performance and they've got drivers that no other os can compete with.

intel's graphics chips are relatively simple. it makes me wonder how much performance nvidia or ati/amd cards have that is not in use, including in windows.

[eugeni_dodonov]

intel's graphics chips are relatively simple.

Oh my... I wish they were so. Out of all those 1400000000 transistors in Ivy Bridge (http://www.anandtech.com/show/4798/i...8b-transistors) and 1160000000 transistors in Sandy Bridge, a pretty large share is responsible for graphics. I'd say that starting with the Intel Core-based generation of GPUs, these are not simple at all.

[schmidtbag]

Oh my... I wish they were so. Out of all those 1400000000 transistors in Ivy Bridge (http://www.anandtech.com/show/4798/i...8b-transistors) and 1160000000 transistors in Sandy Bridge, a pretty large share is responsible for graphics. I'd say that starting with the Intel Core-based generation of GPUs, these are not simple at all.

i said relatively simple, meaning, compared to nvidia and amd/ati, they are simple. but yes, they are complicated otherwise.

[chuckula]

i said relatively simple, meaning, compared to nvidia and amd/ati, they are simple. but yes, they are complicated otherwise.

Intel's graphics hardware is likely almost as complicated as anything from Nvidia or ATI. In Sandy Bridge the hardware lacks DX11/OpenGL 4.0 features like tesselation, but the complexity is probably close to Nvidia or AMD in other areas. Modern graphics cards really get their power from having a HUGE number of execution units repeated over & over in silicon.

Intel's graphics execution units are of similar complexity to AMD and Nvidia, but the latter two get much better performance for two major reasons:
1. AMD and Nvidia typically devote many many more resources to the graphics and include many more copies of the same execution units than Intel does. Even in an integrated design like Llano, AMD has more transistors devoted to graphics than will be present in Ivy Bridge (and over twice as many transistors as are used in Sandy Bridge). That's one reason I'm predicting that Ivy Bridge will get close to Llano's graphics performance, and maybe beat it in low-power envelope applications, but will not beat Llano in higher-TDP designs like desktops where all the GPU resources can be used.

2. AMD and Nvidia devote FAR more resources to getting the drivers working at optimal performance than Intel does. This is actually Intel's biggest failure in the graphics world. It's not that Intel's hardware is that terrible (it's not high-end, but it's OK for the intended market Intel aims it at). Instead, Intel is often way behind the curve at getting proper driver support out. This appears to be changing for the better, but Intel is a big entity and it takes a while to really turn things around.

[smitty3268]

holy crap seriously, do the intel graphics chips have a bottomless pit of spare performance because it seems like every release has had a noticeable performance improvement. all they really need to focus on at this point is improving high resolution performance and they've got drivers that no other os can compete with.

intel's graphics chips are relatively simple. it makes me wonder how much performance nvidia or ati/amd cards have that is not in use, including in windows.

Part of that is that Michael keeps showing the same performance improvements over and over again, as features like RC6 are enabled, he tests, then disabled when problems are found on some systems.

Part of it is that the drivers used to be really, really bad.

Intel's drivers on other OS's are still pretty bad, although they are definitely improving. It's interesting to see that the Intel Linux drivers are now in the position of probably being the best compared to Windows or OSX, at least in OpenGL. Windows D3D support isn't too bad these days either.

[alazar]

I windows, the performance of a nvidia gt 525m is not too far away from the Intel HD3000.

In linux I need to use Bumblebee, so the nvidia got worse performance, but the Intel here makes 2/3 the way the nvidia does.

I really hope rc6 get enabled soon, I want to use linux more instead of Windows just for the battery life.

[darkbasic]

I really hope rc6 get enabled soon, I want to use linux more instead of Windows just for the battery life.

Is it so difficult to boot with i915.i915_enable_rc6=1?

[alazar]

Is it so difficult to boot with i915.i915_enable_rc6=1?

No, what is difficult is not having desktop drawing problems with it.