k62 on old board, can't tell if L2 cache is enabled for real

[rnimz]

Ok I have this old socket 7 (not super7)PC-Chips motherboard, (and I know it is a POS, but I got it for free), and it was running a cyrix MII 300, which was horribly slow when I wanted to play any games at all, so I went out and bought a k62 500 (since the board has 83.333 mhz bus settings I figured I would run it at (x6) 500), well I stuck it in, set the jumper right (2.2V, x2(x6), 83 mhz) and started her up, well it didn't work. I spent the next day trying to get it to work, and flashed the bios (using the cyrix) several times with no luck. I was about to give up but I figured I would just quick try it at 66mhz bus even though the cyrix worked fine at 83, and boom booted up and was rock solid. A little later I tried testing it out to see how fast my brand new chip was, and you could tell even though it was at 400 this one had an fpu!! Well I ran what few things I had laying around and I was really shocked to find that it was running slower than my k6-266 laptop (cpu mark99), so I started up win98 and went into UT, the best I can get still (with a voodoo3 3000 pci & 160mbs RAM) is about 15-19 fps at 640x480 with everything set to medium. I think this is a bit slow but I really don't have anything to compare it too since I only have a laptop, and that doesn't have a voodoo3 or anything close. I am pretty sure that the reason it won't run at 500 (or 450) is because it is a crappy mobo and although set to 2.2V the cpu isn't getting enough power to make it past 400. Well I am ok with 400 if I have to be, but after downloading lots of little cpu tests and utilities not a one of em says that I have any L2 cache, it is for sure enabled in bios and I am not sure if it is on or off, but it is the only thing I can think of to expain why my system is running so slow. Any input would be great, if I am not clear enough let me know and i will clarify, thanks in advance.

 

[DaddyG]

You should see the L2 cache size if its enabled on the first BIOS splash screen.

 

[Assimilator1]

Also Sisoftsandra should tell you about your L2 cache in the mainboard info section

 

[rnimz]

SiSandra doest say anything about my lvl2 cache, nor does anyother program, which is why I tend to think that it isn't actually on, however I have not checked to see if it comes up on the splash screen, I will reboot and watch for it, hopefully I can catch it we will see... Otherwise anyone know where you can get really old copies of bios? maybe I have flashed a bios that made it not work (though it said it was for my board and revision), I mean this is a PC-Chips board, they arn't exactly the most on top of things, well we will see.

 

[rnimz]

OK well I have done more testing, and well the level 2 cache is enabled, but that still doesn't explain why it is slower than my k6 266 laptop, and why it simply won't boot at anything other than 66 mhz fsb when I have ran it with another chip at 75 and 83, no matter what the speed the chip is running at internaly I can't even get the system to boot windows once, or linux for that matter, is there a logical explaination for this? I am simply stumped. If anyone knows why this might happen, please let me know, thanks.

 

[Assimilator1]

Does your K6-2 @ 400 show up as being slower thatn your k6 266 in Sisoft sandra? (I'm not familiar with cpu mark99).
Will the K6-2 boot up at ,eg 4x83MHz=332MHz ? if so ,like you said it maybe a power supply problem stopping you getting 500.
Doesn't there website give any ideas?

 

[rnimz]

Well I ran Sisandra on the k6 and yeah it is slower than the k62 400, but real world performance (especially in games) is worse, Also I tried the same thing you were thinking, I have set it as low as 2.5x 75 and still it won't boot when the k62 is running at anything but 66 mhz bus, I can't figure it out, its not like the board won't run at it at all, cause the cyrix will do it fine. The mobo manufacturer is of no help at all, they didn't even have bios up for it for 3 months while they redid their site, I am baffled as to when it won't boot at anything higher than 66, also it isn't my RAM cause I pulled out the stick of PC66 and left in the high quality PC100, if you have any ideas lemmie know. Thanks.

 

[BurntKooshie]

I had a similar problem when I (tried) to run a K6-III on my POS (non-super) socket 7 mobo (still my only machine at this point, with an M2 300).

What I determined was that the L1 cache was actually disabled. This is entirely possible, because there were enough changes to the K6 core when they moved to the K6-2 and K6-III. It requiers a BIOS update to get the L1 cache enabled, or a program to do it for you (the one I used, that is, until the chip mysteriously died on me a day later, was powertweak, but I did not register it - my chip wasn't alive long enough to make use of the software).

That's a slightly different situation, because I was able to boot into windows, albiet slowly.

Try gaming on an M2 300 with gaming, in Unreal Tournament on the Team AnandTech gaming server, with a winmodem and a V2. That's true gaming bliss [/end sarcasm]

I feel your pain...I hope that it is one day releaved, but I can't help any more than that .

 

[Assimilator1]

Interesting point BK ,

rnimz

Disable your L1 cache in the bios ,that should heavily impact its performance ,if not then the bios hasn't enabled it.BTW you could do the same test to the L2 cache too.

BTW ,which model & revision mobo do you have ?

 

[rnimz]

I tried disabling both L1 and L2 a couple of days ago, and well I know they are enabled because when I had the L1 disabled it took about 4-5 minutes to startup, and when I had the L2 disabled it dropped benchamrks down to 1/2-2/3 of performance, so I don't know what it could be.

 

[Peter]

Since I've been using quite a few PC-Chips mainboards (and still do), let's start over.

What board is it after all? We need to identify that, so I can give you the appropriate hints.

Regards, Peter

 

[rnimz]

OK sorry I forgot to include that, it is a PC-Chips M-571 (not LMR) revision 7.0 and the latest bios from the PC-Chips website, just for clarification, it has a SiS TX Pro II chipset, which includes the integrated video (SiS 5597/5598) and a C-Media 8330 sound chip. Right now it has the following attached to it: a voodoo3 3000 pci, 3-COM Etherlink III 10/100 pci, one 8gb samsung drive and one 6 gb maxtor drive, 128 MB Dell PC100, and 32 MB PC66 IBM RAM, both salvaged from other machines. Hope these help.
Also the bios revision is from mid 1999, I forget what date exactly but it is the latest one available.

 

[Poof]

Ummm.... I know that people underclock CPUs all the time and this might already be common knowledge (I have a K6-2/500 myself), and maybe what I'm saying is totally irrelevant to the L1/L2 cache discussion or the fact that you're trying to do a 83Mhz X 6 multiplier to get to 500.... but that chip normally runs on a 100 Mhz bus and perhaps there are issues with that fact that you're running into. More info here.

 

[Assimilator1]

rnimz

Well ,I've looked at the Website & the manual ,and all I can say is that PC chips support is a load of sh*t! ,it says ah heck all about what the new bioses support compared to there previous versions.I'm afraid I've currently run out of ideas & options.
I would still guess though that board isn't stable enough to run the cpu above 66 MHz(after all the higher clock speed will draw more current).
One last thought K6-2's from 400 (and some 350's) & upwards had the CXT core ,maybe your bios upgrade only supports the earlier K6-2's properly??

Maybe Peter can give a more definative answer

 

[rnimz]

well it seems to support the CXT core fine, since it remaps 2x to 6x it is a CXT, plus they didn't make non CXT k62s above 400 mhz, I can only guess that it is a really wierd quirk, the board is rock solid (well as rock solid as it gets) with the cyrix MII running at both 83 and 75 bus speeds, but even if I clock the k62 at 375 (4.5 * 83) it just beeps at startup, and the farthest it will ever go is detection of drives after the bios splash screen. Thanks for all of the support by the way.

 

[Fardringle]

It may be that your PC66 RAM simply can't handle the 83Mhz bus speed you are trying. See if you can borrow some PC100 RAM from a friend (or some smaller computer shops will let you take your box in and 'try before you buy') and if it will then boot properly at the 83Mhz bus then you've found your problem...

 

[rnimz]

Well I have already tried that, one of my sticks is pc100, and I have taken out the pc66 stick, and that didn't help, also the cyrix runs fine with both in at 83 mhz bus...

 

[Peter]

OK, here's the scoop.

The M571 uses the SiS 5598 chipset. This chipset, being from a time when Cyrix had the only CPUs with FSB faster than 66, does not work reliably with other processors at 75 or 83. M571 v7.0 has a later revision of the 5598, which is officially rated 83 MHz, but still Cyrix-only.

Some people are lucky with AMDs at those "high" speeds, but most people find that they're stuck at 66 MHz bus (6.0x multiplier for 400 MHz max) with non-Cyrix processors.

Regards, Peter

 

[rnimz]

well that would explain it, thanks for the info, I really apreciate all of the help, looks like I am stuck with 400 until I can scrounge up the cash for a good board and a duron, then I think i'll throw the k62 500 in my girlfriend's machine and run it the way I was tring to here, oh well at least I am not stuck with the cyrix, which was ok for webstuff and mediorce for programing, but definetly not good for games. Well thanks again.

 

[Assimilator1]

Peter

Could you give me a link to that info about the SIS chipset please?

rnimz

Damn thats a bummer being stuck at 400 MHz.Though you know that K6-2 would be MUCH better at SETI than your old cyrix would of been ,hint ,hint

 

[rnimz]

Well I don't know where to find info about the SiS 5597/5598, I have searched all over SiS's website, but have been unable to find anything useful, I also downloaded the data sheet, and searched it all over, and I can't find anything in there, isn't anyhelp either, although they have actually put the info on the board back up, (it was gone for like 3 months while they redid their site, by the way the site still sucks). So I am unsure if there is anything that I can do to really fix it, and it looks like I'll have to wait until I can afford my duron.

 

[Peter]

No link - my own investigation.

Cyrix CPUs have a signal timing tweak feature called "SADS" - Slow Address Strobe.

BIOS on any mainboard built with SiS 5598 chipset (or 5597, 5581, 5582, all very similar) enable that at 75 or 83 MHz. Disable it (can be programmed at runtime), and blam, instant crash.

AMD processors can't slow down the ADS signal, and presumably hit exactly that problem.

The very latest batch of SiS 5598 chips seems to have that fixed, but you won't find those anywhere else than on PC-Chips M571LMR, which is the last active design on the market using that chipset. Note that this is very different from M571.

Regards, Peter

 

[rnimz]

well sounds like I am out of luck, thanks for checking for me, its always comforting that someone else at least knows why something isn't working. I think I will have to live with the 400 for the moment, but I turn 21 this month and if I get some cash as a present I am eyeing up a epox 8KTA+ which from everything I have read is very stable, supports changing the multipiler and most importantly is ~$100, and a duron, then I will throw this 500 in my girlfriends IBM, which has an older ali chipset, and we will see if we can get it to do 6.0 x 83, I think I have a better shot since its newer, and there is even a jumper in it to switch the pci clock back to 33 when you are at 83 bus, and then I'll just throw her k6 300, in this POS. Thanks for the help, I really apreciate it, its very dificult to know everything on your own.

Thanks,

-Reid


edit: can't spell, had to fix em.

 

[Assimilator1]

Peter

Thanks for the info ,how did you discover the 'SADS' tweak?

 

[Peter]

Well, during daytime, I'm a BIOS developper - and when I get to spend some time on other people's work, I'm kind of curious about what they did and why they did it

Looking at my mom's M571, I found that its BIOS sets SADS when above 66 MHz, then played with it, and found it necessary. My own M560's BIOS doesn't (uses ALi Aladdin IV chipset), so obviously it's not a CPU requirement, but more so a chipset one.

Regards, Peter