You have to think about the time of writing the manual: at that time there probably weren't memory modules bigger than 64mb. Later TX/VX chipsets maxxed out at 64mb only so having 4x64mb was a lot!

but as long as modules meet the rest of the criteria in the manual they should work fine imho. The cpu and the board should both be able to handle the 512mb.

Nemo1985 wrote:

Hello, everyone, I'd like to install the max memory amount on this mb, I have the revision 3.10 with a pentium 200 mmx installed […]
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Hello, everyone, I'd like to install the max memory amount on this mb, I have the revision 3.10 with a pentium 200 mmx installed and 32mb of edo 50ns but i'd like to have more.
I already bought and installed the tag ram (W24257AK-12) which would let me reach 83mhz bus without issues.
I'd stick with 50ns memory, I found some different memories on ebay but i'm not sure which one I should buy since the mb require the notched end.
According to the manual it supports 64mb sticks on every slot, so less than the max cacheable area of 512.
Any suggestion?
Thanks

AFAIK the TAG ram has nothing to do with the ability to reach 83MHz FSB.
RAM speed does (albeit you can alter timings to make it easier) and just about every other component you have in the computer =)
My HDD slowly corrupts data at 83MHz but 75MHz is fine.
And with board revision 3.1 are you sure you really need the extra TAG ram to be able to cache >64MB ?
I know my rev 3.1 has the TAG RAM socket, but it still caches 128MB just fine.

Also if you want to avoid sketchy e-bay sellers check out "1-800-4-memory".
Also remember that the HX chipset supports ECC (!) wich helps with larger RAM amounts.

I know my rev 3.1 has the TAG RAM socket, but it still caches 128MB just fine.

430HX requires two TAGs to cache all 512mb.

512mb works well on it.

Back in 2005 i build the beast:
Asus P/I-P55T2P4 rev3.10. Patched BIOS, TAGRAM chip and 256kb COAST module installed. 83mhz FSB.
AMD K6-III+ 550ACZ. Downclocked to 500mhz (83x6).
4x128mb doubleheight SIMM modules by Samsung. FPM, True ECC, 128mb. 512mb in total.
IDE HDD 3.5" Seagate barracuda 120gb.
3DFX Voodoo4 4500 32mb PCI.
AWE32 CT2760 + 2x16mb 30pin SIMM + DB50XG
Gravis Ultrasound MAX 2.4
Disney Sound Source
SiliconSoft Jr.
3COM 3C905-TXM PCI
Promise Ultra133 TX2
DVD-RW Plextor PX-716A
TEAC 5.25" + 3.5" dual drive
ZyXEL U-336E+

Thank you for all the answers.
I know that the tag ram is not the only thing that will let me reach (or not) the 83mhz bus, but I read that the 15 ns tag ram would have been troublesome so I'm gone with 12ns.

aleksej wrote:

512mb works well on it. [...] 4x128mb doubleheight SIMM modules by Samsung. FPM, True ECC, 128mb. 512mb in total. [...] […]
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512mb works well on it.
[...]
4x128mb doubleheight SIMM modules by Samsung. FPM, True ECC, 128mb. 512mb in total.
[...]

Where did you find them on ebay I find dimm edo (??) but not simm of such large capacity.

Can confirm the max amount is 512mb as that's what I currently have in my motherboard (same as yours, rev 3.10),I also have 83mhz FSB

If your mobo doesn't have a coast module slot (blank pins on mobo) it should already be capable of accepting 512mb of ram.
If you have a coast slot but don't have a coast module installed then you can only go as much as 256mb ram. (4 x 64mb sticks)
If you install a coast module in the coast slot you will be able to install 512mb of ram. (4 x 128mb sticks)
If you don't have a TAG chip installed your system will only cache the first 64mb of ram, the rest will be accessed slower.
If you have a AMD k6-2+ or k6-3+ then you don't need to bother with coast modules or TAG chips.

I've got 4 x 128mb edo modules bought from ebay -
https://www.ebay.com/itm/256MB-2x-128MB-EDO-S … 353.m2749.l2649
These sticks I bought actually have 50ns chips on them (look closely at the sellers photos, -5 on the end)

Also I have an AMD K6-3+

I use to have 256mb of ram, to be honest going up to 512mb made no difference in performance or speed so unless you really need the extra ram for certain applications maybe just stick with 256mb.

read this page http://www.wowohl.de/kalle/rev3.htm
it is a little confusing to read due to authors english, but then again my post could be worse.

Thank you very much for your info, they are very clear.
Unlucky this seller is from US while I live in Europe, also it seems he has some stocks and the memories could be different from the pictures.
This is my mb: https://imgur.com/a/tcq1GVD
As every later revision it doesn't have the coast slot because it has 512kb already and I installed the tag ram.

As every later revision it doesn't have the coast slot because

Actually some small amount of revision 3.x boards had the COAST module.

The Serpent Rider wrote:

As every later revision it doesn't have the coast slot because

Actually some small amount of revision 3.x boards had the COAST module.

Thanks, I didn't know, all the rev 3.1 I saw they were without COAST module.

bofh.fromhell wrote:

[...]

AFAIK the TAG ram has nothing to do with the ability to reach 83MHz FSB.

Yes it does - it's also a RAM chip with a max speed. If you have a slow Tag, it'll limit your clocking as much as slow RAM or cache. This is an issue as COAST was a transitional technology at the very beginning of PLB cache, when bus speeds were rarely above 66MHz. By the time >=75MHz was commonplace, PLB cache was just soldered onto the motherboard.

dionb wrote:

bofh.fromhell wrote:

[...]

AFAIK the TAG ram has nothing to do with the ability to reach 83MHz FSB.[/auote]
Yes it does - it's also a RAM chip with a max speed. If you have a slow Tag, it'll limit your clocking as much as slow RAM or cache. This is an issue as COAST was a transitional technology at the very beginning of PLB cache, when bus speeds were rarely above 66MHz. By the time >=75MHz was commonplace, PLB cache was just soldered onto the motherboard.

Exactly.
Also not every sram was made equal so a "bad" one could have limited you to less than a speedy 83mhz. Albeit it was hard to gauge which IC was the limiting factor. At least in the case of the tag being the bad guy a daring "enthusiast" could have soldered in a "better" one.

amadeus777999 wrote:

Exactly.
Also not every sram was made equal so a "bad" one could have limited you to less than a speedy 83mhz. Albeit it was hard to gauge which IC was the limiting factor. At least in the case of the tag being the bad guy a daring "enthusiast" could have soldered in a "better" one.

Fortunately with COAST it's pretty simple - if you can clock higher without COAST stick in there, either the tag or the cache itself - but in any case the module - is to blame. If not, your bottleneck is somewhere else.

Sorry for the bump, I received today the second p55t2p4, another rev 3.10 (out of curiosity is there a rev 3.11?).
It was bundled with a Pentium 166 vanilla (no mmx).
I have some doubts about the voltage, the jumpers are in STD 3.4V and 2.8V, wasn't this the voltage of pentium mmx?
I'm really confused, the pc was used in a production dos machine for years (the dallas chip still works) but with the wrong voltage?
I tried to get some informations about the vanilla pentium voltage but they give confusing info: 3.3 3.1* 2.9*.
Under the cpu there is no mention of voltage, just:
fv80502166
SY037/VSU

Any help?
Thanks!

It's probable that the jumper settings are just wrong for voltage, and the CPU has been happily running under voltage all these years.

Especially if it is one of the later production run CPUs.

canthearu wrote:

It's probable that the jumper settings are just wrong for voltage, and the CPU has been happily running under voltage all these years.

Especially if it is one of the later production run CPUs.

It's what I thought, but if the original voltage is 3.3, it's very undervolted, also the manual mention 3.2 as max voltage supported... I'm really confused...

Good evening, I need your good advice.
I bought 2 tag ram for my 2 p55t2p4 mb.
This is the first one: https://www.ebay.it/itm/1pcs-W24257AK-12-W242 … AM/172752215909
This is the second (still on his way): https://www.ebay.com/itm/1pcs-W24257AK-10-DIP … AK/273513638379

How can I check if those are true chips and not fake chinese rebranded stuff?

I suddenly suspect they might not original parts, since the price is so low and even on aliexpress they usually cost 10 dollars instead of 2.

Thanks

You can't really be sure - but at this price it doesn't matter, just see if the do the job or not. Generally this sort of old stuff sold cheap just works, regardless of whether some genius thought it was a good idea to re-do the label.

dionb wrote:

You can't really be sure - but at this price it doesn't matter, just see if the do the job or not. Generally this sort of old stuff sold cheap just works, regardless of whether some genius thought it was a good idea to re-do the label.

You are right, but if they are cheap chinese clones maybe they can't handle the 83mhz bus.. Can I use CACHECHK with more than 64mb to see if it works properly?

Edit: as suspected, I put 128mb of memory and used CTCM it happens something weird:
Jumper 2-3 + tag ram: 64mb cacheable
Jumper 1-2 + tag ram: system gone crazy, keyboard wasn't answering controls and when I finally was able to use ctcm it crashed with a memory access violation
Jumper 1-2 without tag ram: everything ok and 64mb cacheable

Is there anyone with more than 64mb memory and working tag ram, willing to test the system with ctcm?

Thanks.

The cache in the second eBay link looks similar to mine. Mine work with an 83 MHz FSB. Hi me passes. Memtest passes. CTCM shows all 64 mb is cacheable. But there is no guarantee you’re works - test it.