Matrox cards capable of "AGP 2.5x" (on 440BX)

[Bosanek]

Hello,

I have an excellent i440BX based motherboard (Asus P3B-F), and it "semi-officially" supports even 150 MHz FSB. I intend to try it with an "EB" edition of a Coppermine P3 (the one which works at 133 MHz FSB).

As you may recall, 440BX officially supports up to 100 MHz. But this board has special frequency dividors for PCI and southbridge, which enables them to work at 33 MHz even at 133 MHz FSB. But AGP has a dividor of either 1/1 (for use with 66 MHz FSB) or 2/3 (for use with 100 MHz FSB). When using 133 MHz with AGP factor of 2/3, AGP works at 88 MHz (instead at 66 MHz).

AFAIR, this frequency was too big for most of AGP 2x/4x cards. I remember that GeForce cards had the biggest "yields" in terms of supporting this frequency.

But how do Matrox cards stand in this criteria? Is it known which models are good for this and which are not?

In addition to this question, I have one more specific - I have recently ordered a Matrox G400 MAX (G4+MMDHA32) card. Will it be suitable for AGP at 88 MHz?

And while I am asking - could a Voodoo 3 3500 sustain this AGP setting?

[Admiral]

I'm not sure, but won't the AGP bus be reduced automatically to 1x if it can't handle the high frequency ?

If not, this was one of the solutions at the time, shift to 2x or 1x AGP (bios, power strip, some other tool).

[UtwigMU]

Both G400 and Parhelia work very well with 133MHz FSB on BX boards. Otherwise Matrox cards were known to work very well with overclocked AGP bus on BX. I tried G400 16SH AGP2x and Parhelia AGP4x. I have also G400 AGP4x but I was out of BX boards when I got it. I posted one of them or maybe was it GF2MX with 150 FSB with PII 350 @ 525 but it was unstable at that clock.

If you're really into BX you should get a Tualatin Celeron and wire mod it. For a while I was running Celeron 1.1@1.46 and Parhelia on Abit BE6II RAID (replaced caps). I still have BX rig around, it's a Thinkpad A21p with 1600x1200 screeen, 512MB, Ati Rage Mobility and PIII 850.

Probably the coolest BX rig would have been Asus P2B-D dual slot1 with high end coppermines.

[Bosanek]

To Admiral: the transport mode of AGP (1x, 2x, 4x) has nothing to do with the "raw" frequency. AGP frequency is 66 MHz in all AGP transport modes (1x, 2x, 4x, 8x). In other words, decreasing the mode to 1x should not be helpful because the raw frequency is still at 88 MHz. That is a problem at the electronics level, not at the protocol level.




To UtwiqMU:

Thank you very much for giving me so much useful information in so little text. It appears that I got an answer from just the right person (and an ex-co-countryman ).


As all "sub-1000 MHz" P3/Celeron CPUs are dirt cheap today, I see no need to complicate matters to myself by using an "E" (100 MHz) edition of P3 and pumping it to 133 MHz, because I could directly obtain an "EB" P3 (133 MHz) and just pump the mainboard. In this case, everything should be working at nominal level (CPU, PC133 RAM, PCI, ATA, other int. peripherals) except AGP and the chipset itself.


Because of my very limited experience with P2/P3 (Slot 1 & Socket 370) plaftorms (my main "area of interest" were/are Socket 7, Socket 8 and early (Thunderbird) Socket A platforms), and also limited overclocking experience (I have never pushed any PC beyond 5-7%), I do not feel "worthy" enough to venture into an advanced/tualatin BX enhcanment yet.


The current CPU in this board is P2 350 MHz at 100 MHz FSB with a Matrox G250 (no heatsink). This CPU will stay here for the next few weeks because I am currently too busy to search for a P3 CPU. Could I *safely* raise this CPU to 133 MHz (= 465 MHz) without any additional cooling (now it works at ~ 35 celsious) or voltage raise? Or how much voltage raise is required? I am really afraid of changing voltage to a particular value, unless that change/value is verified/known to be safe with the same CPU as the one which I am using.


The next step (in summer), which I would probably do, would be to acquire as fast "EB" coppermine P3 as possible (866 MHz at least). Since this is a Slot 1 board, I suspect that Slot 1 EB CPUs are rather rare in comparision with Socket 370 EB CPUs, so I will probably need a slotket. Is any slotket good for this task, or to they differ in any sense (CPU/freq. support, electrical quality, voltage regulation, etc.)?

[UtwigMU]

I was using PII 350 overclocked to 466 on DFI P2XBL between 99 and 03. No voltage mod since board didn't allow it. If your CPU is fine it should usually run stable @466 without voltage mod, see base on overclockers.com if it hasn't been scrapped yet. Temps were about 42-44 under load. Latter I got Abit BE6II RAID and BX133 RAID (socket 370). BX133 is teh win since it's 370 and you can more easilly find CPUs. Unfortunately it's from bad caps period so most have probably been thrown away.

Generally Abit slocket was considered the best. I was using something called Super Slocket370 for a while. The difference in slockets is SMP and FSB support. If you want to run Tualatin PIII or Celeron, you can try to get Powerleap slocket that properly supports them. It also supports SMP AFAIK. Tualatin Celeron has 256MB of L2 and supports SSE just like Coppermines, only drawback is no SMP. There were also server 512kB PIIIs but they are hard to find. Generally you can overclock 1.0A or 1.1A to 133MHz.

Here's shot of my 1.1A@1.46GHz on Abit BX133 RAID.


Here's the legend with new caps. I latter managed to fry AGP slot by dropping screw on graphic card.

[Admiral]

To Admiral: the transport mode of AGP (1x, 2x, 4x) has nothing to do with the "raw" frequency. AGP frequency is 66 MHz in all AGP transport modes (1x, 2x, 4x, 8x). In other words, decreasing the mode to 1x should not be helpful because the raw frequency is still at 88 MHz. That is a problem at the electronics level, not at the protocol level.

I know, though with some video cards and i440bx the system was more stable running only one overcloked channel.

[Bosanek]

I tried my P2 350 on 466 and it works just fine (at around 47-50C). All RAM modules are PC133, I doubt that I could have achieved this with any PC100 RAM.

If I undrestood you correctly, the only requirement to run a Tualatin Pentium 3 / Celeron on a BX Slot 1 board is to obtain a Slotket which supports Tualatin CPUs? Nothing else? No BIOS flash, no hard-wiring, no voltage mods, etc.?

Are you sure that Tualatin Celerons can not work in SMP without some "extreme" modifications?

You know that for a Tualatin CPU you need a "Tualatin capable" motherboard (with a "T" chipset, like 815T, 133T, 266T, etc.), but I heard that 512 KB (S edition) Tualatins also require special BIOS support for them on the motherboard (in other words, not every "Tualatin capable" motherboard is capable of running a 512 KB Tualatin). Is this true!? This reminds me of the situation with 1 MB Pentium Pro editions, which, AFAIK, could not run in any Socket 8 motherboard (although AFAIK it used the same voltages etc.), because it required additional BIOS support for its cache or something.

That screenshot speaks for itself. I suppose that your Celeron @ 1.46 with 133MHz FSB should equal the Pentium 3 256 KB Tualatin 1.4 (Celeron's disadvantage of slower cache and no hardware prefetch should be nullified by additional 66 MHz, or not?).

Do you know which is the fastest Celeron which can be raised to 133 MHz FSB? I know a man who claimed that he had used a Celeron 1.3 simply overclocked at 1.73 for three years (it was a VIA 133T based board).

[UtwigMU]

If you get Powerleap or Upgradeware adapter, Tualatins work.

Celerons will not work in SMP, I think you need PIII-S with 512kB of L2. Not sure if they'll work on BX but PII already had 512kB of L2 cache (half CPU speed though).

Generally Celerons topped at 1.4-1.5 so 1.0A and 1.1A should work, with 1.2 it's slim chance you'll need extreme overvolt. I couldn't get my 1.4 much above 1.5 even with overvolting.

[Bosanek]

Thank you very much for all provided information.
I used to think that Tualatin core could go all up to 2 GHz (I've even heard some "sailor's" tales about running Celeron Tualatins at 2100 MHz (14 x 150)).

Now I know that the guy who claimed that he ran a Celeron 1.3 at 1.73 without any additional tweaking was probably lying.

How warm/hot is your Celeron at 1.46 when it is under load? What cooling do you use on it? And, what is the maximum "safe" temperature range for a Tualatin core?

[UtwigMU]

As you can see in screenshot with stock Intel cooler withot case after 60h of Prime95 @1.45V (stock=1.475 but Abit board only had .05 steps) temperature was 37°C

[dZeus]

I tried my P2 350 on 466 and it works just fine (at around 47-50C). All RAM modules are PC133, I doubt that I could have achieved this with any PC100 RAM.

If I undrestood you correctly, the only requirement to run a Tualatin Pentium 3 / Celeron on a BX Slot 1 board is to obtain a Slotket which supports Tualatin CPUs? Nothing else? No BIOS flash, no hard-wiring, no voltage mods, etc.?

Are you sure that Tualatin Celerons can not work in SMP without some "extreme" modifications?

You know that for a Tualatin CPU you need a "Tualatin capable" motherboard (with a "T" chipset, like 815T, 133T, 266T, etc.), but I heard that 512 KB (S edition) Tualatins also require special BIOS support for them on the motherboard (in other words, not every "Tualatin capable" motherboard is capable of running a 512 KB Tualatin). Is this true!? This reminds me of the situation with 1 MB Pentium Pro editions, which, AFAIK, could not run in any Socket 8 motherboard (although AFAIK it used the same voltages etc.), because it required additional BIOS support for its cache or something.

That screenshot speaks for itself. I suppose that your Celeron @ 1.46 with 133MHz FSB should equal the Pentium 3 256 KB Tualatin 1.4 (Celeron's disadvantage of slower cache and no hardware prefetch should be nullified by additional 66 MHz, or not?).

Do you know which is the fastest Celeron which can be raised to 133 MHz FSB? I know a man who claimed that he had used a Celeron 1.3 simply overclocked at 1.73 for three years (it was a VIA 133T based board).

if you want to run a tualatin, make sure your board's VRM supports the voltage required by the tualatin. afaik most (all??) slotkets don't provide a VRM that will supply the right voltage if the motherboard doesn't support it.
EDIT: I see the powerleap adapter has this VRM that might be needed. 'VRM 8.4' and later boards can use a cheaper slotket without VRM though.