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Old 07-11-11, 12:12 PM   #1
AireTamStrm
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Join Date: Nov 2006
Posts: 49
Default GTX470/GTX465 Terrible 2D Performance NVIDIA driver 275.09.07

I have had hell getting 2D to perform acceptably between a GTX470 and GTX465. The behavior is as many other threads describe: scrolling, resizing windows, or 2D-heavy operations just destroy the system. If I'm watching a video on one screen, on either GPU, scrolling a web browser on another screen (another GPU) will make the video studder and X will consume the CPU time of an entire core.

My BIOS by default configures large overlapping MTRR records. I have a bug with them on this, and in the mean time I've killed the uncachable and overlapping ranges by configuring them manually:

Before

reg00: base=0x000000000 ( 0MB), size= 4096MB, count=1: write-back
reg01: base=0x100000000 ( 4096MB), size= 1024MB, count=1: write-back
reg02: base=0x0c0000000 ( 3072MB), size= 1024MB, count=1: uncachable
reg03: base=0x0bf800000 ( 3064MB), size= 8MB, count=1: uncachable


After

cat /proc/mtrr
reg00: base=0x000000000 ( 0MB), size= 2048MB, count=1: write-back
reg01: base=0x100000000 ( 4096MB), size= 1024MB, count=1: write-back
reg02: base=0x080000000 ( 2048MB), size= 1024MB, count=1: write-back

I've heard both sides of the fence: MTRR matters, and MTRR doesn't matter. I have PAT support, so I figure the latter, but I also I figured hunting down that issue couldn't hurt. The MTRR settings take effect before the nvidia kernel module is loaded, but I'm not sure if its "too late" at that point. gtkperf benchmarks identically in both the "corrected" and default MTRR settings, suggesting that if MTRR is the problem, its too late.

As a side note: This is on a multiprocessor NUMA board (dual E5520 Xeons) with two IOHs. You will see that via the lspci output in the attached nvidia bug report. Also, I have a pair of GTX 260s collecting dust that I upgraded from, these /seem/ to not have the issue. I cannot recall 100% that they did or did not have the issue, so I will test them thoroughly when I get home.

I'm really lost as what to test next, any feedback at all would be extremely helpful.
Attached Files
File Type: gz nvidia-bug-report.log.gz (125.2 KB, 70 views)
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