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Single vs Dual memory channel - no effect ?

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Raistmer:

--- Quote ---That IMO, is where the Dual channel benefit is supported by your numbers, in reducing the 'Worst case' scenario

--- End quote ---
Unfortunately, there is another factor that can cause slowdown it seems.
[That is, I think I just didn't see worst case for dual channel still, cause I rebooted OS recently]
I've seen speed degradation when system is up for long time for hybrid build. There this effect pretty big. But it seems it presents for CPU-only app too.
So I would not trust timings that were recived w/o OS rebooting (or count them separately from "just rebooted" ones).
Why exactly I see such speed degradation - it's another (and pretty important) question...
[ ADDON: windows memory pool becomes fragmented??? ]

And yes, it seems CPU AP not much sensitive to memory speed directly (on my CPU). I trying to study what system components have big impact on SETI performance and what not.
For now it seems (at least for AP) that one can save money and buy usual memory, not the best possible, provided he managed to get CPU with really big cache :)
Today I will complete experiment proposed by Richard and post new data.

Jason G:

--- Quote from: Raistmer on 15 Nov 2009, 03:59:00 am ---...
Why exactly I see such speed degradation - it's another (and pretty important) question...
[ ADDON: windows memory pool becomes fragmented??? ]
...

--- End quote ---
Hmmm, yes I don't really see with with CPU app & long uptime, so will give it some thought.  Yes I think aggressive memory management of windows might be related ( which vmm gets less aggressive with successive Windows versions) so heap management accumulating stale crap could be an issue, which is why I was originally trying to bypass a layer by avoiding CRT & using vmm directly instead. 

Just a theory: TLB Misses for code (rather than data), caused by accumulated entires, could be exacerbating front end stalls, which would indeed IMO suffer after longer uptime due to later windows not so aggressively paging out, so accumulating more stale entries for rarely accessed services & drivers etc.   Over Christmas, will be putting some special performance counters to see if we're getting certain kinds of stalls in the decoding that are prone to happen on Core2,  If not then will keep looking for the culprit.   If front end stalls is a problem (OS/uptime induced or otherwise), then might need to do a bit more reading on how to rectify the situation.  Not sure what part new OS features like Super-fetch might play, but will have a chance to look in a couple of weeks, when migrating to Win7.

Jason

Raistmer:
In my current config swap enabled ( :o usually I disable it completely if host has enough memory) and SuperFetch stopped (setted to manual instead of automatic).

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