Optimising memory management to use cpu cache more efficiently

[Gorstak]

https://pandoon.info/en/optimisatio...-et-activer-les-caches-l2-et-l3-de-son-cpu-3/

After reading the above article, I opened regedit, and my l2 was at zero, and l3 was non existant...

Would someone care to explain?

 

[Vya Domus]

The cache is a hardware component that can't be disabled/enabled, not in modern CPUs and not by the operating system (and not under normal circumstances). If that would have been the case and the caches were disable your computer would be massively slower. This is probably a legacy thing for embedded use , don't bother.

 

[phanbuey]

The cache is a hardware component that can't be disabled/enabled, not in modern CPUs and not by the operating system. This is probably a legacy thing, don't bother.

^
This

Also ur cpu doesn't have l3.

 

[cucker tarlson]

^
This

Also ur cpu doesn't have l3.

of course it has.

 

[Gorstak]

seems my pc is running faster now, even my mouse movement is smoother

 

[Vya Domus]

Placebo. The caches on Intel CPU are inclusive, meaning that if one is disabled none of them would work.

 

[Gorstak]

not necessarily disabled, have you read the article? Simply put, windows memory management wasn't optimised for my system....it doeesn't touch the cache, it changes windows memory management.

 

[FireFox]

seems my pc is running faster now, even my mouse movement is smoother

How it comes?

For sure not because you enabled l2/l3

 

[Gorstak]

is it a troll fest today? Read with understanding please. I didn't enable nor increase cache on cpu, I optimised windows memory management for my system. And now I'm noticing my ram usage and swap usage is way lower then what it was before restart.

 

[Vya Domus]

Believe what you want, I am trying to explain to you that on your CPU changing anything about the cache is not possible. The caches and their functionality are not exposed to the operating system or to any software, it's a hardware function that is transparent to the code executed. The only thing that I can think of about that registry edit is that it may enable some different code path for something that was compiled differently with other optimizations enabled.

But I am convinced it doesn't affect performance in any tangible way.

And now I'm noticing my ram usage and swap usage is way lower then what it was before restart.

Download more RAM ? I have a feeling you're trolling. None of the things you say make sense.

Here is a link that was posted in the same article : https://msfn.org/board/topic/25766-registry-myths-2-setting-the-l2-cache-size/

This is not related to the hardware; it is only useful for computers with direct-mapped L2 caches. Pentium II and later processors do not have direct- mapped L2 caches.

SecondLevelDataCache can increase performance by approximately 2 percent in certain cases for older computers with ample memory (more than 64 MB) by scattering physical pages better in the address space so there are not so many L2 cache collisions. Setting SecondLevelDataCache to 256 KB rather than 2 MB (when the computer has a 2 MB L2 cache) would probably have about a 0.4 percent performance penalty.

 

[Gorstak]

I'm not sure what the issue is here. I might be writing in turkish and failing to notice it. Nobody touched cpu nor it's cache. What was changed was software, specifically windows memory management settings. This isn't a jesus being resurrected, it's a simple tweak for your os to work a few % more efficiently, maybe more, I don't know, since I didn't test it yet. There is probably a line in the code somehere that says something like for 512 then that....what I did is order that part of code to use for 3072 then that...

A simple optimisation, nothing else.

 

[Vya Domus]

Again, believe what you want. If you're convinced your PC is faster and is using less RAM, wonderful, I guess.

 

[Gorstak]

You can't make your cpu go faster, but you can make windows use 100% of it, instead of bottlenecking it...

and now i have to see if there is a hidden setting or something that will make use of RAM as additional cpu cache.

 

[silentbogo]

You can't make your cpu go faster, but you can make windows use 100% of it, instead of bottlenecking it...

and now i have to see if there is a hidden setting or something that will make use of RAM as additional cpu cache.

https://docs.microsoft.com/en-us/pr...ro/windows-2000-server/cc938581(v=technet.10)
Scroll down to the end of the page.

These settings were obsolete since Vista (or maybe even earlier) and only for old platforms (probably the ones that still had controller for external cache expansion). Nowadays cache is fully managed in hardware (e.g. by CPU itself).
Plus, you have to understand that cache is not memory. You can't "use" it, it's just there to fetch and store some recently-accessed data while all you see from the "platform" or "user" point of view is memory(RAM) access. You don't even need to be aware of how much L1/L2/L3 you have or whether you have it at all, all you do is read from RAM or write to RAM and CPU does the rest.

 

[dorsetknob]

You can't make your cpu go faster

Of Course you Can
depending on Motherboard you can Overclock
you cannot increase the CPU l2 cache its fixed as its on CPU Die.

Time to Polish my Troll killing Club as its covered in blood and brains

 

[TheoneandonlyMrK]

I'm not sure what the issue is here. I might be writing in turkish and failing to notice it. Nobody touched cpu nor it's cache. What was changed was software, specifically windows memory management settings. This isn't a jesus being resurrected, it's a simple tweak for your os to work a few % more efficiently, maybe more, I don't know, since I didn't test it yet. There is probably a line in the code somehere that says something like for 512 then that....what I did is order that part of code to use for 3072 then that...

A simple optimisation, nothing else.

Epic fail then bro.

ALLWAYS test before, record /save results.
Effect change.
Then retest and record/save results.

Then come on here and convince the world.

As has been stated , modern processors have extensive lists of settings that get read on boot.

Many registry keys are set to 0 by default because that default is auto.

And the auto behaviour to find out cache sizes by the os is to check the CPUs internal codes as it boots , same for core count.

The tangible gain's you say you have mean naught because you can't validate they happen.

 

[Aquinus]

Show me numbers and I might be inclined to think about why, otherwise everyone else has already said what's on my mind. Windows has no control over if cache is used or not. That's up the the CPU or BIOS if disabling cache is supported, but most modern hardware doesn't let you disable things like L2 cache anymore because it would detrimental to performance and this isn't something that can typically be altered while the system is hot.

is it a troll fest today? Read with understanding please. I didn't enable nor increase cache on cpu, I optimised windows memory management for my system. And now I'm noticing my ram usage and swap usage is way lower then what it was before restart.

Anecdotal evidence is not evidence. Restarting your machine will always use less memory and swap because it's starting fresh. It's not like anything is cached in swap or anything. Use the computer for a bit and you'll see that number grow, even if you close everything you already opened.

 

[newtekie1]

These registry entries are from way back in the day, when you could actually add cache to the system manually. They are leftovers from the Windows 9x days. They don't do anything in modern versions of Windows, and haven't for years. The OS now reads the CPU and it's capabilities on the fly. Don't believe me? Open the modern Windows Task Manager on Windows 10, it will list the cache sizes of your CPU. So it knows what they are, and how to use them.

 

[Kursah]

is it a troll fest today? Read with understanding please. I didn't enable nor increase cache on cpu, I optimised windows memory management for my system. And now I'm noticing my ram usage and swap usage is way lower then what it was before restart.

I would like to add that if there's a reason that experienced and knowledgeable members are doubting a very legacy feature on a modern OS and system, there's likely a good reason for it.

If all you have to show for it is nothing more than claims from what is more likely placebo, there's not much for you to actually argue or support. That's on you to prove, nobody else. No need to degrade your own topic if folks don't believe you, be constructive and get some proof to share.

It also seems you will not provide actual before and after results or evidence to support your claims, yet want to resort to calling others trolls and taking the low road by choice. It won't end well if you continue to make that choice.

You may want to re-read our forum guidelines before posting here or in any topic. I have it conveniently linked in my sig.

 

[MrGenius]

I can Enable/Disable CPU L1 & L2 Cache in the BIOS on my Syntax s651m(SiS 651 chipset) motherboard. If I disable them the OS hangs on boot.

 

[R-T-B]

I'm can to Enable/Disable CPU L1 & L2 Cache in the BIOS on my Syntax s651m(SiS 651 chipset) motherboard. If I disable them the OS hangs on boot.
View attachment 112712

Fun fact, doesn't really hang, just goes really, really slow. You might get a post screen in around 12 hours...

 

[MrGenius]

I did a quick test to see if it makes any difference. Surprise surprise!!! It doesn't...

 

[Gorstak]

Ok. I did some testing and there is no difference in any test. I was wrong and that article is bogus.