hello, Sorry if this has been asked before. Are there plans to write an optomized version of PD for the new 64 bit desktops/laptops? (G5/AMD 64 FX)
What's the reason to go 64 bit with Pd? Do you need more than 4GB per process? Otherwise the 64 bit version of Pd would most likely be a bit slower than the 32 bit due to the additional overhead of 64 bit pointers (it's minor but still there).
<blockquote> HyperTransport: A high-speed bus without detours
Unlike all Intel CPUs, which communicate with the Northbridge via a regular parallel FSB, AMD's Hammer relies on a HyperTransport interface. The serial interface with a variable bitrate allows the SledgeHammer to attain a data transfer rate of 3.2 GB/s - in both directions simultaneously. This results in a total bandwidth of 6.4 GB/s. By comparison, the Pentium 4 with 533 MHz FSB allows a maximum data throughput of 3.97 GB/s - but not in both directions simultaneously. The bandwidth of the serial interface is designed to be flexible. AMD gives the server version of the Hammer three HyperTransport ports. The entire data traffic of the Hammer processor runs through the HyperTransport interface and the integrated memory controller. In order to let the neighboring CPU gain direct access to its system memory, the Hammer uses the XBAR switch. For commands and addresses, the XBAR switch has further 64-bit buses available.
</blockquote>
I thought that the processor could move more per cycle, like the difference between the 486 sx and dx.
Also, neither the PPC 970 or AMD FX are available for laptops and probably won't be for quite some time.
I hear summer 04 for the G5 laptop, and there already is a AMD64 laptop (just not FX). Alienware wont say when they'll make a FX laptop...
The scoop at tomshardware maked amd look really good, in 64 bit mode, and I know there are writeins for linux 2.6 on AMD 64FX...
Really? It made Quake faster? ;)
http://www.tomshardware.com/cpu/20030923/athlon_64-22.html#opengl_benchmarks
Toms and anandtech usually have a pretty limited selection of mostly synthetic bemchmarks that have little to no relvance to Pd and real-time audio and video.
Granted. Perhaps someone should ask them...
Any thoughs, as I have had a hard time getting video processing and audio synthsis running in realtime on the same laptop (or at all with some packages that use libquicktime and ffmpeg, \'cause thoes two fight)? This could be the answer.
64 bit won't help you there at all - having libs that are decently coded will though. However, I have been compiling GEM for the G5 since September, and have tested the changes on occasion. Nothing about the 64 bit nature of this chip helps the performance, but the massive bandwidth really makes the Altivec and GL fly.
I find it hard to believe that the ability to move twice as much information in one pass wouldnt help the ability to create and redraw the screen, and build an audio sample in shorter time. Doesnt the ability to move 64 bits into a register and perform manipulations to each set of 32 bits whilst there, improve on moving 32 bits into registers, processing, moving out, moving another 32 bits in, processing, moving out?
-thewade
On Wed, 24 Dec 2003, thewade wrote:
I thought that the processor could move more per cycle, like the difference between the 486 sx and dx.
The difference between the 486sx and the 486dx was that the dx had an embedded FPU similar to the 387, while the 486sx didn't.
However, the difference between the 386sx and the 386dx was, well, different, but marketing reused the same sx/dx labels. The dx was the "real" 386, with a 32-bit data bus and 32-bit address bus, while the sx had a 286-compatible box, so a 16-bit data bus.
The scoop at tomshardware maked amd look really good, in 64 bit mode, and I know there are writeins for linux 2.6 on AMD 64FX...
http://www.tomshardware.com/cpu/20030923/athlon_64-22.html#opengl_benchmarks
I doubt Quake was really in "64 bit mode". I think it ran simply in 32 bit mode, but that this CPU handles 32 bit faster, just like all preceding ones. Eg: a 486SX-16 was about the same as a 386DX-33; a Pentium-66 was about as fast as a 486DX-120.
Doesnt the ability to move 64 bits into a register and perform manipulations to each set of 32 bits whilst there, improve on moving 32 bits into registers, processing, moving out, moving another 32 bits in, processing, moving out?
Performing the same thing twice on two halves of a 64-bit register, is the kind of thing you find in MMX. Performing two things on two different 32-bit registers is the kind of thing you find in all Pentiums. (In both cases, though, there are a lot of limitations on how it can be done).
OTOH, the K8's 64-bit is about this:
working on 64-bit integers as you would on 32-bit integers (not something you'd really care about in Pd...)
busting the 4-gig memory limit (having 64-bit pointers).
The actual data bus of the CPU has been for many years independent of that, with all those caches and such. The Pentium-66 already had a 64-bit data bus although it was a 32-bit CPU. If I am reading correctly, the K8 has a 1-bit bus but with a mad clockrate: 3.2 gigabytes/second would mean at least 3.2*8 = 25.6 GHz on a serial port (!), if I understand correctly.
Mathieu Bouchard http://artengine.ca/matju
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Mathieu Bouchard -
thewade