On Sat, Jan 10, 2009 at 6:02 AM, Rob OpenSuSE <rob.opensuse.linux@googlemail.com> wrote:
You're talking a lot of crap, frankly.
As you've become rude, I'll just suggest you clue up by finding some CPU architecture explanations.
Oh really? Wow. I didn't know I could spend 11 years designing and implementing embedded systems on resource-constrained designs, and not know a thing about how computars works! I will get right onto the inter-tubes right away and find out more!! Your little dissertation on how memory access has gotten slower relative to older processors is naive at best, and wrong if you sat down with a real chip and looked at it's real performance. A 100 cycle latency for accessing memory on a cache miss - is not and cannot take longer on a chip capable of running 3 billion cycles a second compared to one which may only do 30 million or even 300 million with the same latency. This is simple math; latency relative to cycles taken has gone up (from 1 or 2 up to perhaps several hundred in designs like the Pentium 4) but the data transfer capabilities of the memory controller, the size of the L2 cache itself on these designs, means that 1 cycle scaled up would take far longer a percentage. I really do not see how you could equate, at a stab, a 30MHz processor taking 20 cycles from a 16MHz, 16-bit memory bus being faster at accessing memory than a 3GHz processor taking 200 cycles from a 1066Mhz 64-bit (or 128-bit) memory bus, even in relative terms, and you can poke around with performance counters in x86 and PowerPC processors and see this proved out in reality. The "Finnish democoder competition" method of coding where every cycle counts and everything has to load in 64k really won't make KDE run faster, nor does it explain why increased USE of memory (which is not down to the desktop itself, since KDE4 for example uses 10% less memory here than KDE3, which has "less features") would slow a system down simply because it has to access more of it. I dare say cache management algorithms both in hardware and software have advanced enough that your point is absolutely moot even if it WERE true on a basic, high-school textbook level. -- Matt Sealey <matt@genesi-usa.com> Genesi, Manager, Developer Relations -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org