On 14 Oct 2001, at 13:40, Francois Gouget wrote: > Nope. It is still 0.18 microns (see Anandtech). If you have a > source > claiming otherwise I would like to see it. They plan to switch to 0.13 > early next year. Then, they should be able to increase the frequency > big time.
Oops, I got that wrong. Sorry. Comes of trusting a failing memory :( > > > > which means keeping it cool should be a bit easier. > > They say it runs 20% cooler. It would probably run much cooler if > they had switched to 0.13 microns. The reason they provide for the > lower power consumption, is small architectural optimizations. But > what I find most interesting is its low power consumption when idle. > They introduced it for the laptop market but AFAIK it is also present > in the regular desktop processor. 20% cooler = 60K? There should be frost on the heatsink ... Do you mean 20% less power consumption? That seems reasonable. Denser circuits allow lower voltages which does result in a lot less power consumption per element. But there's less area for the waste heat to get out, so the cooling problem doesn't neccessarily go away... > This poses a kind of dilemna since the energy used to run prime-net > is no longer energy that would have been wasted otherwise. So you have > to make a choice between preserving the environment and running > prime-net (to some extent). This is the case with most if not all of the mainstream PC CPUs made in the last couple of years. If you don't use the floating point unit the FPU turns itself off, there is a large drop in current draw and the CPU cools down. Alternatively, with many "micro" desktop & laptops, you need to turn on an extra fan if you run programs which exercise the FPU (as Prime95/mprime undoubtedly does). The CPU current consumption of a 1.2GHz T'bird will drop by ~30W when the FPU is inactive. However, given that the power drawn by the system as a whole is likely to be >150W (_much_ more if you have a large CRT monitor), the power saving by the system as a whole is not likely to be hugely significant. > > [...] > > Note particularly that e.g. 256 MB can be made up of one bank of 256 > > MBit, two banks of 128 MBit or four banks of 64 MBit RAM chips; > > expect a performance difference of 5% - 7% between these > > configurations even if the chip access speeds & timings are > > identical. More banks are faster. > > Hmmm, you need to distinguish motherboards that merely have > multiple > memory slots, from motherboards that have more than one data path to > the memory. The only motherboards that I know of that can do the > latter are some RDRAM based motherboards and the Nvidia nForce. > In all other cases (the more common one?) putting multiple DIMMs > should not affect performance one way or another. No, this is the construction of individual DIMMs, not occupancy of DIMM slots, though populating two DIMM sockets with _identical_ single-bank DIMMs can get you the same performance boost. VIA Apollo Pro chipsets can definitely take advantage of multibank DIMMs; the BIOS provided with some mobos (particularly Abit) allows you to tune the chip banking manually. I found on my Abit KT7A, with two identical double-bank SDRAM DIMMs installed, setting quadruple banking improved the speed of mprime by 7% compared with the default setting. > > Yes, AMD better implement SSE2 in their processors soon. Why? Might there not be a better way? The point is that a PII-350 has more than enough power to do what most business users need, whilst tackling the problem of updating complex displays very rapidly (for games) is better handled in dedicated hardware in the graphics adapter. What I would like to see in a CPU is a means where you could upload your own microcode, enabling design of specific instruction sets to handle particular problems very efficiently. For numerical work, the capability to handle _very_ long integers directly would be extremely useful. Regards Brian Beesley _________________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
