From mboxrd@z Thu Jan 1 00:00:00 1970 Mime-Version: 1.0 (Apple Message framework v749.3) In-Reply-To: <3e1162e60605050901h76225ba5g968a975bdcbd608f@mail.gmail.com> References: <10b3044aa926a9c4115682ad88c1983a@quanstro.net> <999CCCBC-2504-4212-9629-E63C2A79BCA5@telus.net> <3e1162e60605050901h76225ba5g968a975bdcbd608f@mail.gmail.com> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <59C58783-A3E0-4D01-A3BE-FFC24A212762@telus.net> Content-Transfer-Encoding: 7bit From: Paul Lalonde Subject: Re: [9fans] nvidia scrolling performance Date: Fri, 5 May 2006 09:21:57 -0700 To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu> Topicbox-Message-UUID: 4d787b94-ead1-11e9-9d60-3106f5b1d025 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The GPGPU stuff that is making the computation much more accessible, but at least in my field (games - uh make that real-time interactive graphical simulations) if you give me more throughput near video ram, I'll be sorely tempted to (surprise) use it to make more or better pictures. The interesting thing about the GPU is that it exposes a (fairly) strict streaming computation model in which the user really only has control over the computation kernel, and very little control over the iteration construct. That makes using the high levels of parallelism relatively easy and efficient. The challenge is in expressing non- trivial algorithms in streaming ways. Aaron Lefohn's Glift suite (http://graphics.idav.ucdavis.edu/graphics/publications/print_pub? pub_id=837) is a nice wrapper around that material for more general data structures on the GPU. The downside is that you had better have a C++ compiler that does templates well. I'm really hoping that we can find a way to get our users off the C/C+ + bandwagon (and that includes the high-level shading languages as well) and using something that can express the required computations more naturally. There are some promissing-looking functional approaches, but there's a huge barrier to adoption if it doesn't look like C. Paul On 5-May-06, at 9:01 AM, David Leimbach wrote: > On 5/5/06, Paul Lalonde wrote: >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> Aw, but I'd claim all that fancy 3-D graphics stuff is real >> computation :-) >> But yeah, GPU abuse for general purpose computation is just plain >> scary. I thank my lucky stars that there is plenty of FLOPS to go >> around in the Cell's SPUs. >> > > Eh, nvidia's working on making the GPUs more accessible (via > compilers, kind of like Cell) for more general purpose computation. > > The problem with FPGA, GPU, and "non-local" coprocessing cores is > usually the moving of data to them fast enough. Cell shouldn't have > this problem and with the new hypertransport stuff coming out, it > looks like one can easilly do NUMA like things inter-chassis too. > > I don't know if this is cost effective, but streaming parallelism to > special coprocessors can be a big win in HPC. > > Dave > >> Paul >> >> On 5-May-06, at 8:46 AM, erik quanstrom wrote: >> >> > if i were doing real computation, i wouldn't use a gpu i'd use a >> > cpu. ;-) >> > >> > - erik >> > >> >> 8G/s? Nowhere near enough. Enough for text, but try doing real >> >> computation using that GPU... >> >> PS3 is running 25G/s bi-directional. Those bits move. >> >> >> >> -----BEGIN PGP SIGNATURE----- >> Version: GnuPG v1.4.1 (Darwin) >> >> iD8DBQFEW3W0pJeHo/Fbu1wRAoOzAJ9C4d5WBnPm4hH1scoknQI1sFfuTgCgqC9c >> Ft6mIE9ogrlaD9ltrNkMmjg= >> =qWgd >> -----END PGP SIGNATURE----- >> -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Darwin) iD8DBQFEW3ulpJeHo/Fbu1wRAtbrAJ0RH5SpW4ZIx0W7BZIh3QXCRXt5MwCfYLVG 4DsnaEAu+s0hp/wAVsJZ5+U= =R5Qr -----END PGP SIGNATURE-----