CPU Cache Disabling

[N3RO]

Hi,

With old-school motherboards we are able to disable the CPU Cache.

With these new motherboards (P35, ...) we are not able to disable the CPU Cache on the BIOS.

Someone knows how to disable the cache @ windows?

I tried to change the value of the key "SecondLevelDataCache" in the registry to "0", but doesn't work..

[]s,

[swaaye]

"SecondLevelDataCache" is only for ancient hardware with on-mobo L2 cache.
http://support.microsoft.com/kb/183063

I'd imagine the reason the option in the BIOS is gone is because it would cripple your CPU rather immensely. And there really is little reason to turn it off. It used to be used for better DOS speed support. If you wanted to gimp your system for old DOS apps, say.

[N3RO]

"SecondLevelDataCache" is only for ancient hardware with on-mobo L2 cache.
http://support.microsoft.com/kb/183063

I'd imagine the reason the option in the BIOS is gone is because it would cripple your CPU rather immensely. And there really is little reason to turn it off. It used to be used for better DOS speed support. If you wanted to gimp your system for old DOS apps, say.

True.

But I really need to turn it off (not about DOS apps). I've my reasons

Do you know how to disable it?

Regards,

[Khaotic]

Sure
Take a hammer and punch to the left side of your CPU and tap lightly.

Other than that - I don't think there are even any software plugs that will disable the cache on a CPU. The closest we get is buying a CPU with a lesser amount of cahce - such as the Celeron's and Allendales.

[pak]

If you need cache disable really bad, maybe you can try running an older system?

--pak

[RAW-Raptor22]

Like a Cacheless Covington Celeron... XD

[swaaye]

Why do you want to disable the cache? If it's some DOS app, use DOSBOX instead. I've only seen a few utilities that can disable L2 cache, and those were back in the AMD K6 days

[IvanAndreevich]

As far as I know, this is not possible on modern processors.

[DerekT]

I've my reasons

Care to let us in you your reasons?

[Nikolasz]

As far i know those reasons are for Wery good overclockings by mhz when L2 cache is dissabled.

20-30% more in mhz

[cpuz]

Disabling L2 is processor specific, and for that reason needs to write to a MSR.

Besides, you can disable all caching with the control register 0 (CR0), that works on all CPUs.
But doing this results in a drastic slow down. And when I say drastic, I mean it

[Nikolasz]

Hey cpu-z

Yes agree abaut slowing, and you will have to wait for windows boot up much much longer. And same gows to all task when you start it.

[swaaye]

Yeah I used to disable the L2 on the slot-based Pentium II and IIIs with off-die cache. You could go a little higher. It wasn't practical because you lost way more in speed than you gained from clock. Also on K6-III systems with crappy, barely overclockable mobo L2 cache disabling the mobo cache wasn't a bad choice cuz the K6-III cached so much better anyway and you could overclock the bus more that way.

But man there's a reason CPUs have L2 cache. Their efficiency goes down the tubes in an insane way without it. Your Core 2 will turn into something like a Pentium 90! (ok maybe not quite that bad lol)

[Nikolasz]

Atleast now ppl know old_scool stuff, and they can overclock into much hier frequencies.(nubs)
Besides some old/basic real (those wich can olny be run olny in dos)dos proggys need L2 dissabled, to awoid errors.