L2 cache and Win XP?

[xent0r]

In another forum [for a game] I came upon this post and
thought I would ask here.:

"PLEASE READ if running WinXP
Kendrick Crownguard

Joined: 19 Jun 2002
From: Canada
NWN Game Owner
Posted: Tuesday, 13 May 02:17PM
An aquaintence of mine just brought to my attention a very
interesting little tidbit of information. In Windows XP
(Home and Pro) and in Windows 2000, the L2 cache (which
you pay for) is turned off. I don't have a clue why, but a
few people have noticed a very significant increase in
speed when enabling it.

Whenever editing the registry, please do a backup just in
case. This does not create any keys, just modifies an
existing key. Using Regedit go to the following location.

HKLM\
system\
currentcontrolset\
control\
sessionmanager\
memory management

The Value in question is SecondLevelDataCache (which is
set to 0).

If you have Intel P4 processor than the cache value should
be 512. For AMD, look at your receipt or box to see what
the 2nd level cache should be. For many it is 640. On 4
machines tested, all experienced a significant ~20%
increase in performance.

Please let me know if anyone has a reason for this gross
oversite on Microsofts part. Please also let me know what
kind of performance boost you get.

I mean we have all payed for the cache, why should we not
be able to use it? What possible reason could Bill have
for turning it off? Any incites please let me know. "

[Terry]

This tweak is only useful for older processors with the cache located
external to the CPU
"xent0r" > wrote in message
...
> In another forum [for a game] I came upon this post and
> thought I would ask here.:
>
> "PLEASE READ if running WinXP
> Kendrick Crownguard
>
> Joined: 19 Jun 2002
> From: Canada
> NWN Game Owner
> Posted: Tuesday, 13 May 02:17PM
> An aquaintence of mine just brought to my attention a very
> interesting little tidbit of information. In Windows XP
> (Home and Pro) and in Windows 2000, the L2 cache (which
> you pay for) is turned off. I don't have a clue why, but a
> few people have noticed a very significant increase in
> speed when enabling it.
>
> Whenever editing the registry, please do a backup just in
> case. This does not create any keys, just modifies an
> existing key. Using Regedit go to the following location.
>
> HKLM\
> system\
> currentcontrolset\
> control\
> sessionmanager\
> memory management
>
> The Value in question is SecondLevelDataCache (which is
> set to 0).
>
> If you have Intel P4 processor than the cache value should
> be 512. For AMD, look at your receipt or box to see what
> the 2nd level cache should be. For many it is 640. On 4
> machines tested, all experienced a significant ~20%
> increase in performance.
>
> Please let me know if anyone has a reason for this gross
> oversite on Microsofts part. Please also let me know what
> kind of performance boost you get.
>
> I mean we have all payed for the cache, why should we not
> be able to use it? What possible reason could Bill have
> for turning it off? Any incites please let me know. "


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.480 / Virus Database: 276 - Release Date: 5/12/2003

[Terry]

From an arstechnica article) One of the most infamous NT tweaks since the
introduction of NT4 has got to be the "L2 cache" tweak, a lone registry
entry which stipulates the amount of L2 cache (or secondary cache) that the
OS will make use of. Well, as with many things in life, the effects of this
tweak are not so black and white. If you're using a processor that
implements a direct-mapped L2 cache design (like Pentium I's), then this
registry adjustment is indeed for you. However, if you own any Intel
processor post-PI, or any modern AMD processor (K6-2 and newer), then your
processor is using a set-associative L2 cache design, and thus you need not
specify your L2 cache size. Let me explain.
If you choose not to futz with the registry key in question, the OS will
call on the HAL (Hardware Abstraction Layer) for retrieval of the L2 cache
size when you boot your computer. If this happens to fail, a default value
of 256KB is used for all logon sessions on that boot session. This is where
the myth that NT can only use 256KB of L2 cache comes from. But it's false.
See, the HAL is able to retrieve the processor (L2) cache from any processor
using the set-associative cache design, it's only the relatively few
processors out there with direct-mapped L2 caches that the HAL won't chat it
up with. Thus, this tweak only applies to a select number of people anymore
(like people with Pentium I procs between 166-233MHz, as lower rated procs
had only 256KB cache).

"xent0r" > wrote in message
...
> In another forum [for a game] I came upon this post and
> thought I would ask here.:
>
> "PLEASE READ if running WinXP
> Kendrick Crownguard
>
> Joined: 19 Jun 2002
> From: Canada
> NWN Game Owner
> Posted: Tuesday, 13 May 02:17PM
> An aquaintence of mine just brought to my attention a very
> interesting little tidbit of information. In Windows XP
> (Home and Pro) and in Windows 2000, the L2 cache (which
> you pay for) is turned off. I don't have a clue why, but a
> few people have noticed a very significant increase in
> speed when enabling it.
>
> Whenever editing the registry, please do a backup just in
> case. This does not create any keys, just modifies an
> existing key. Using Regedit go to the following location.
>
> HKLM\
> system\
> currentcontrolset\
> control\
> sessionmanager\
> memory management
>
> The Value in question is SecondLevelDataCache (which is
> set to 0).
>
> If you have Intel P4 processor than the cache value should
> be 512. For AMD, look at your receipt or box to see what
> the 2nd level cache should be. For many it is 640. On 4
> machines tested, all experienced a significant ~20%
> increase in performance.
>
> Please let me know if anyone has a reason for this gross
> oversite on Microsofts part. Please also let me know what
> kind of performance boost you get.
>
> I mean we have all payed for the cache, why should we not
> be able to use it? What possible reason could Bill have
> for turning it off? Any incites please let me know. "


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.480 / Virus Database: 276 - Release Date: 5/12/2003

[grahamilton]

LOL
what forum was that in?

"xent0r" > wrote in message
...
> In another forum [for a game] I came upon this post and
> thought I would ask here.:
>
> "PLEASE READ if running WinXP
> Kendrick Crownguard
>
> Joined: 19 Jun 2002
> From: Canada
> NWN Game Owner
> Posted: Tuesday, 13 May 02:17PM
> An aquaintence of mine just brought to my attention a very
> interesting little tidbit of information. In Windows XP
> (Home and Pro) and in Windows 2000, the L2 cache (which
> you pay for) is turned off. I don't have a clue why, but a
> few people have noticed a very significant increase in
> speed when enabling it.
>
> Whenever editing the registry, please do a backup just in
> case. This does not create any keys, just modifies an
> existing key. Using Regedit go to the following location.
>
> HKLM\
> system\
> currentcontrolset\
> control\
> sessionmanager\
> memory management
>
> The Value in question is SecondLevelDataCache (which is
> set to 0).
>
> If you have Intel P4 processor than the cache value should
> be 512. For AMD, look at your receipt or box to see what
> the 2nd level cache should be. For many it is 640. On 4
> machines tested, all experienced a significant ~20%
> increase in performance.
>
> Please let me know if anyone has a reason for this gross
> oversite on Microsofts part. Please also let me know what
> kind of performance boost you get.
>
> I mean we have all payed for the cache, why should we not
> be able to use it? What possible reason could Bill have
> for turning it off? Any incites please let me know. "

[grahamilton]

next he'll be telling plp about the IRQpriority tweak

"xent0r" > wrote in message
...
> In another forum [for a game] I came upon this post and
> thought I would ask here.:
>
> "PLEASE READ if running WinXP
> Kendrick Crownguard
>
> Joined: 19 Jun 2002
> From: Canada
> NWN Game Owner
> Posted: Tuesday, 13 May 02:17PM
> An aquaintence of mine just brought to my attention a very
> interesting little tidbit of information. In Windows XP
> (Home and Pro) and in Windows 2000, the L2 cache (which
> you pay for) is turned off. I don't have a clue why, but a
> few people have noticed a very significant increase in
> speed when enabling it.
>
> Whenever editing the registry, please do a backup just in
> case. This does not create any keys, just modifies an
> existing key. Using Regedit go to the following location.
>
> HKLM\
> system\
> currentcontrolset\
> control\
> sessionmanager\
> memory management
>
> The Value in question is SecondLevelDataCache (which is
> set to 0).
>
> If you have Intel P4 processor than the cache value should
> be 512. For AMD, look at your receipt or box to see what
> the 2nd level cache should be. For many it is 640. On 4
> machines tested, all experienced a significant ~20%
> increase in performance.
>
> Please let me know if anyone has a reason for this gross
> oversite on Microsofts part. Please also let me know what
> kind of performance boost you get.
>
> I mean we have all payed for the cache, why should we not
> be able to use it? What possible reason could Bill have
> for turning it off? Any incites please let me know. "