Zrychlení OS Win2k/XP/Win2K3
Co říkáte na tohle? Zrychlení systému o 10-20%...
http://www.7-max.com/
od autora:
I write 7-zip compression program. And some time ago I discovered that memory access is slower than it can be. It's because windows uses 2-levels mode inside CPU for virtual memory management. But all modern CPUs allow 1-level mode for virtual memory management. It's slightly more complex for system (windows) to use such mode, since it requires some more smart algorithms. But there is some speed gain for some programs. So I rewrite that code to use 1-level mode (4 MB pages).
CPUs that have advantage in sorted order:
Duron (most advantage)
Celeron
Pentium 4
Athlon
Athlon-64 (less advantage).
When L2 cache is small advantage is larger.
About L2 cache.
It can be such performance for some application without/with 7-max:
512 KB L2 - 100%/110%
256 KB L2 - 95%/108%
64 KB L2 - 80%/100%
NO L2 - 50%/80%.
These numbers are not real, just to show trend.
I don't plan to change 7-max. It's too difficult application. And it's luck that it works on some systems. Purposes for 7-max were to check
1) Can Windows work faster? Answer - yes.
2) How much faster it can work? Answer - about 10%, but only for special subset of applcations.
Actually Windows 2003/XP-64bit also support such fast mode. But MS haven't implement it fully. So it can work some time just after rebooting for special precompiled applications, but after some RAM fragmentation it still will use old 4-KB mode mode.
Linux developers discuss for 3-5 years about using 4 MB pages
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