Committed bytes is completely the wrong metric to appeal to, since it includes pages that have been committed but have never been touched. Windows reserves space for such pages in the page file (it never overcommits), but saying that it leads to "memory pressure" is ridiculous.
Committed Bytes would be a measure of potential maximum physical memory usage if every process were touching every page that it had available to it. Yes, no process ever does that, but statistically there will be an average fraction of that memory which is touched, so it can be interpreted as a proxy for physical memory pressure. A poor one though, as different processes have different patterns.
As to the Ars forums, with a brief perusal it seems similar to the programming Reddit - i.e. a lot of opinionated and frequently misinformed noise, interleaved with a small amount of signal. It looks like a time sink, to be frank.
But to give Peter his due, I registered with the forums and scanned through his past posts (DrPizza), and I can't find much that I disagree with; I particularly agree with him on the consolification of PC games, and the lack of MW2's appeal to a mature gamer, etc.
edit: and do you think he doesn't know about procexp/perfmon? :)
By bringing the person into this, you turn it into an irrational, emotional thing, where facts don't matter. That's not where you want to be.
And at the risk of extending this thing far beyond its worthy lifetime, that comment you link to proves very little. As I already said:
> Committed Bytes would be a measure of potential maximum physical memory usage if every process were touching every page that it had available to it. Yes, no process ever does that, but statistically there will be an average fraction of that memory which is touched, so it can be interpreted as a proxy for physical memory pressure. A poor one though, as different processes have different patterns.
Allocating a huge bunch of memory and not touching it is one statistical pattern, but it's not particularly common, which is key. It's an outlier, so it isn't strong evidence. On average, committed bytes can be interpreted as a proxy for memory pressure, but like I said, there's likely to be a fair amount of variance there, so it's a poor proxy. There certainly wouldn't be a 1:1 relationship between committed memory and physical memory pressure; if I had to guess, I would guess somewhere like 60% of committed memory should ideally be in physical ram.
For example, my machine has 12GB of RAM, 3.5GB committed bytes total and 2.5GB working set total. But that working set includes both private and shared working set pages - calculating the active working set properly would require dividing shared page sizes by the number of copies in different processes.
But just for fun, I plotted the log of working set values in MB along the X axis, and the log of private bytes in MB along the Y axis, for each process, and this is what I got:
http://imgurl.filetac.com/img/68343980.png
Looks like a pretty close correlation to me - yes, there are some spikes in private bytes, but on average, private bytes is a proxy for committed bytes (I excluded shared pages for confounding reasons, as they are usually things like EXEs and DLLs - not counted against commit charge), committed bytes is a proxy for physical memory usage, which in turn is a proxy for physical memory pressure.
Please explain, for the (majority?) of us who don't spend time at the Ars Forums
http://blogs.zdnet.com/BTL/?p=31024&page=1
FWIW, I never downvoted you - I actually upvoted you when I saw you dropped to 0.
