Dnia 2010-09-27, pon o godzinie 04:42 -0700, jmcarval pisze:
> Hi.
> Installed PyCUDA 0.94.1 in several Linux boxes.
> All have Ubuntu 10.4 with CUDA 3.1 (drv 256.40) and python 2.6.5
> 
> Boxes with 1.1 capability GPUs like 8600GT, 9400 GT or FX850 are ok and some
> user's are already trying them.
> Boxes with 1.3 (GTX280) and 2.0 (GTX480) have dificulties just running the
> supplied tests. On these:
> 
> test_cumath.py passes all tests but is 5 times slower in the GTX280 and
> 40(!) times slower in the GTX480
> As far as I can see, this test never uses float64
> 
> test_driver.py passes all tests but is 4 times slower in the GTX280 and 9(!)
> times slower in the GTX480
> As far as I can see, this test also doesn't use native float64. Testing
> fp_textures seem to be done with some sort of emulation, but I may be wrong
> here.
> 
> test_gpuarray.py is 2 times slower in the GTX280 and fails the dot, sum,
> minmax and subset_minmax tests on the GTX480.

The same problem was mentioned by Peter Schmidtke on 2010-07-21
on this mailing list. IIRC this was because of increased accuracy
of floating point operations on Fermi, and relaxed (by Andreas)
checking of results of operations:

Julien Cornebise (2010-07-21):
> To be honest, I don't have enough experience in pyCUDA to know how
> much the precision issue is a problem -- for what I know, it could
> even be that Fermi are too precise, as I haven't checked how the test
> is done :)

OTOH Andreas wrote on 2010-08-03:
> I must be getting old. The loosening of the test bounds was in
PyOpenCL,
> not PyCUDA. Sorry for the confusion. In any case, test_gpuarray fully
> passes for me on Fermi with current git. Peter, Julien, anyone: are
you
> still seeing problems/failures?

I do not see significant changes in git between versions from 2010-08-02
(ccdc6b) and current one (79c10e).

> 
> Can anybody please point me to some mail thread, FAQ or instalation guide
> that helps me correct whatever I have done wrong?
> 

I would propose to add something to FAQ/wiki, after resolving
this issue.


I have tested PyOpenCL and PyCUDA on ION (9400) with Debian 64 drivers
256.53.

PyOpenCL.
test_clmath and test_array - no problems
test_wrapper - segmentation fault (?)
PyCUDA:
test_cumath, test_driver, test_gpuarray - OK


-- 
Tomasz Rybak <[email protected]> GPG/PGP key ID: 2AD5 9860
Fingerprint A481 824E 7DD3 9C0E C40A  488E C654 FB33 2AD5 9860
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