P/I-P55T2P4

  • Thread starter Thread starter Jonas
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Jonas

Hi,

I have a P/I-P55T2P4 rev 3.0 mobo
256MB RAM
80GB Samsung HD

I have a 256KB Cache Module, without TAG ( I think)

Do I need a TAG SRAM upgrade in order to take full advantage of 256MB EDO
RAM ?
Can I work with both Cache Module + TAG SRAM ?

thanks
 
Jonas said:
Hi,

I have a P/I-P55T2P4 rev 3.0 mobo
256MB RAM
80GB Samsung HD

I have a 256KB Cache Module, without TAG ( I think)

Do I need a TAG SRAM upgrade in order to take full advantage of 256MB EDO
RAM ?
Can I work with both Cache Module + TAG SRAM ?
Click to expand...

This is described in the manual, page 8 and 14.
Basically, you need an external TAG sram upgrade if your cache module
doesn't have one AND you have more than 64MB ram AND you want to have
the ram cacheable. However, if you don't have pipelined burst sram cache
chips, you should not install a tag sram upgrade and your cacheable area
is restricted to 64MB.
If you use a cpu with integrated L2 cache (K6-III/K6-2+/K6-3+) I
wouldn't bother with a tag sram upgrade, the speed gain thanks to the
now-L3 cache is minimal at best - in fact if you have only the 256KB
cache module and no onboard cache it is probably faster if you switch it
off in that case.

Roland
 
Jonas said:
Hi,

I have a P/I-P55T2P4 rev 3.0 mobo
256MB RAM
80GB Samsung HD

I have a 256KB Cache Module, without TAG ( I think)
Click to expand...

I thought rev 3.x T2P4s always came with at least 256K onboard, which
could be expanded with a 256K COAST module then. How much onboard cache
does your board have?
Do I need a TAG SRAM upgrade in order to take full advantage of 256MB EDO
RAM ?
Click to expand...

You need an 11 bit wide tag to obtain full cacheability.
Can I work with both Cache Module + TAG SRAM ?
Click to expand...

It seems so, given Kalle recommends a 256K onboard + 256K COAST + tag
config:
http://www.jump.net/~lcs/kalle/rev3.htm

Stephan
 
Jonas said:
I have a P/I-P55T2P4 rev 3.0 mobo
256MB RAM

I have a 256KB Cache Module, without TAG ( I think)

Do I need a TAG SRAM upgrade in order to take full advantage of 256MB EDO
RAM ?
Click to expand...

Yes, you need an extra TAG RAM in order to get more than 64 Mbyte cached
(or a CPU with L2 cache on chip: K6-2+ or K&-III(+) ).
However, this extra TAG RAM may be placed in the socket of the board
(next to the CPU socket) *or* on the Level2 Cache Expansion module that
can be placed in the long L2 Cache Expansion Slot right of the TAG SRAM
upgrade socket (newer boards don't have this slot but already 512 KB
Cache on board but this is IMHO not true for all Rev 3.0 boards).
Your 256 KB Cache are on board (not on an expansion module). Therefore,
you should get an extra TAG SRAM (if there isn't already one).

You may want to check your uncached memory by using ctcm16r or ctcm17a
from http://www.heise.de/ct/ftp/ctsi.shtml
Can I work with both Cache Module + TAG SRAM ?
Click to expand...
If you mean the on-board L2 cache: yes and you should if you've got more
than 64 Mbyte RAM
If you mean an extra level2 cache expansion in the corresponding slot:
Maybe (it depends on what kind of cache upgrade module you've got. There
are some that have already got an extra TAG SRAM, then you must *not*
place an extra TAG SRAM chip in the TAG RAM socket. Otherwise you
should).

I think it's hard to find an Cache upgrade module but it should be
fairly easy (and cheap) to get a proper TAG SRAM, even new ...

Dont' forget to properly set jumper JP4 for your cacheable area.
Otherwise your board will become unstable.

Stephan
 
I'm a little confused about cache onboard / not onboard, TAG etc.

What I have is a

P55T2P4 rev 3.0
AMD K6-2 400 Mhz CPU, without L2
256 MB EDO Ram
A long 256KB stick module of external cache
No TAG SRAM inserted in the DIP socket next to CPU

What do you consider onboard with this configuration ? I know that there was
P55T2P4 revisions without external cache L2 sockets, but mine has a socket
of that type with a stick module plugged in.

thanks
 
Jonas said:
I'm a little confused about cache onboard / not onboard, TAG etc.

What I have is a

P55T2P4 rev 3.0
AMD K6-2 400 Mhz CPU, without L2
256 MB EDO Ram
A long 256KB stick module of external cache
No TAG SRAM inserted in the DIP socket next to CPU

What do you consider onboard with this configuration ?
Click to expand...

SRAMs that are in sockets on the board or soldered onto it. Is there
really just the COAST socket?

Since you already have more than 64 MiB installed, get ctcm and test the
cacheable area. Should it turn out that only the first 64 megs are
cached, get a tag SRAM. Otherwise, don't bother.

Stephan
 
Jonas said:
I'm a little confused about cache onboard / not onboard, TAG etc.

What I have is a

P55T2P4 rev 3.0
AMD K6-2 400 Mhz CPU, without L2
256 MB EDO Ram
A long 256KB stick module of external cache
No TAG SRAM inserted in the DIP socket next to CPU

What do you consider onboard with this configuration ? I know that there was
P55T2P4 revisions without external cache L2 sockets, but mine has a socket
of that type with a stick module plugged in.
Click to expand...

There are 3 board configuration:
- 512KB onboard cache, no external L2 socket (I believe this was the
most common board in retail market for 3.0 revision).
- 256KB onboard cache, external L2 socket (upgradeable to 512KB)
- no onboard cache, external L2 socket (upgradeable to 256KB or 512KB)

All of these boards need a tag sram update for more than 64MB cacheable
area, with the 512KB onboard version you obviously need the external tag
sram, whereas the other versions could have the tag sram included on the
cache module.
You can possibly figure out by looking at the chips of the cache module
if it has a tag sram (how many chips?).


Roland
 
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