Chipset overvolt on 8k5a3+
 

I have this MB rock solid at FSB 210 MHz , but I want more!! I have a 512 megs module of twinmos pc3200 (BH-5 chips) now at 210 MHz 5-2-2-2 (turbo) timings at 210 MHz.

I can have medium stability at 220 MHz, but stability test like prime95 fails. I'm sure that the ram can do more, and because I have no problems at all at 220 MHz I think that prime fails because the chipset is unstable.

I changed the passive heatsink on the NB with an old (and active) socket 7 cooler with 50 mm fan. Now I want to place passive heatsink on the SB and on the mosfets (I'll do this in few days).

But I want really MORE from my MB. Anyone has an idea about to overvolting the chipset (like on 8rda) ??

I simply need to know which is the vrm .. and I will study how to do the mod. Anyone as any schematics? Do the vrm is similar to any other epox mb?

Thanks all. Bye bye

What VDIMM are you running ?

Re: Chipset overvolt on 8k5a3+
 

I'd like to know that too.

Barix, did you have to do something to prevent AGP tearing?

Vdimm is set to 2,7 volts

what do you mean for agp tearing? Errors or artifacts?

I've done nothing .. I have no problems at all (I'he an Hercules FDX8500LE)

210FSB on a KT333 board! Amazing, even some of the nForce2 with PCI/AGP lock won't run that high!

Anyway, what's the PCI divider at that speed? 1/5 or 1/6? HDD won't live long on an overclocked PCI bus you know.

1/5 divider

I've been feeding my 8k3a+ (kt333) 198MHz for a few months already. No problems at all.

I think I asked about chipset overvolting for KT333 (8k3a) board and it was related to Vmem. Something like that.

Does anyone knows more about it? I'm not very sure but MAYBE KT333 chipset uses the +3.3V. But I'm really guessing here.

VIA 4x AGP chipset uses relational voltage for chipset and memory.

So try 3.2vdimm and hope your memory dont die (like my crucial 2100 did :( )

I tried every combination of vdimm and timings and there's no way to reach stability at 211 MHz.

I'm rock solid at 210 MHz with vdimm 2,7 v and timings turbo (5222). At 211 MHz with vdimm 3,0 v and timings normal (cas 2,5 ecc ecc) I can't have prime95 running without errors. But I can reach 220 MHz without apparent errors. IMHO the problem is not the RAM or the graphics/PCI cards, but a little instability of the chipset over 210 MHz. So I want to overvolt it to obtain it stable...

I don't think over-volting will offer any increase since you have tried higher VDimm (related) to no avail - it seems that you have the ceiling

I don't understand you .. I'm sure that my ram can do more. The only test I fail at 220 MHz is prime95. In the normal use (included gaming) I have no problems. I'm sure that my ram can work without problems over 210 MHz, but my MB isn't able to do this ..

Let me try to overvolt the chipset and I'll see if I was right or not ...

I don't think that we are able to be talking about the same thing here.

Since you apply memory voltage, you are applying chipset voltage - this is not an NForce mainboard or 8x AGP mainboard, this is a different setup - you cannot effect such change in the same way as with 8RDA+ for instance very simply.

You'd have to intercept and seperate a voltage line.

What does this mean?

Are you saying that when i give my memory 0.1v more, my northbridge will get 0.1v more too?

In other words overvolting the ram I overvolt also the chipset?

yep, increasig VDDR will also increase chipset voltage, but I dont think the via chipsets benefit in the same way as nforce2.

With a via chipset problems are more likely to come down to out of spec PCI or pure chipset speed limitation rather than lack of voltage or cooling.

And gains from high VDDR are probably more memory related.

Thanks for the specifics.

Just to comment: when I increase Vmem I have reduced artifacts at high FSB (215 or higher) so that is just to prove that increasing Vmem probably does something to the chipset also.

I don't think you'll be able to hit much higher speeds with KT333 (or any other VIA chipsets for the moment, wait for KT600).

You guys were right!!! :)
 

I was having very little AGP tearing @ FSB 195Mhz +.
I increased the Vdimm a bit, and .... it's running great at 200Mhz. :beer:

Hi
I was getting agp tearing and corruption at 194+MHz in 3D2001.Now having switched Fast Writes on it totally disapeared.
The other weird thing was white lines running up the screen at 195Mhz plus.This was only at post or in the bios.WinXP was fine.I cured this by upping the vmem to 2.7v.Bearing in mind this mem will do 225Mhz at CAs2.5 6T/2T/2T maybe the cure was the increase to chipset and not mem.Will try mem at lower setting to see what happens.Just ran 3dM2001 at 200fsb,no problem.GF2Ti at 250/451.Smiffy

Anyway we're running our PCI at 40+ Mhz and AGP at 80+Mhz. Is there something to worry about?

Hi
Don't think so.All the stuff on the 8K3A used to run on my Abit KR7A.At 195Mhz fsb with only a 1/4 pci divider,so pci at 48.8 and agp at 97.5.And it all still works(apart from the KR7A that is).Having fired up from cold at appears this may be a temp issue.Will pop a fan on northbridge to see what happens.Smiffy

Hey Smiffy, thanx for the reply.

I guess I shouldn't worry too much about 40Mhz PCI and 80Mhz AGP speeds then.

Did your hard drive run at 48.8Mhz without corruption? What brand is it?

HI
They are in fact the dreaded ibm deathstars.I think they handled it much better as they were plugged into an Abit Hot Rod Pro100.I have at the mo i my Junk box an old Maxtor value that would lock unless pci was exactly 33Mhz.It would not even boot at 101Mhz fsb.Most modern cards will handle 80Mhz agp speed although I have heard the new Radeons don't like high agp speeds.Haven't got one,can't comment(although looking for 128MB 9500 to turn hopefully into 9700)The drives you have to chance I suppose.My sis has had trouble with a 60GXP and a 120GXP.My mums 75GXP,supposedly the worst drive ibm made,has been faultless.This is the advantage of the Nforce2 boards,locked pci and adjustable agp speed.XP2400 at the mo in main rig 228MHz X 10.processor does 2480Mhz,still messing with 8RDA+.I think most modern hard drives should handle 40Mhz pci.Smiffy

Cracked it.Northbridge getting to hot.Other hotter than i'd like chips are the clock gen chip and the mem buffer chip,heatsink time.Smiffy

Yeah, cool that northbridge! But why would you cool the clock gen chip?

It did help a bit on my KR7a and theclock gen chip is quite warm on the 8K3A.White lines still here and def temp related I think,starts about 5 mins after start.Only in boot up and bios,none at all under winXP.3D2001 runs fine and artifact tester says no artifacts.At 205Mhz though the mem buffer chip(ICS 93718)wa steaming,nearly burnt my finger.Got a heatsink on it now,may rip off northbridge heatsink and see what conract is like,tried 3 diff vid cards and mem in all slots.Will also hang 60mm fan over parts of board,maybe something else getting hot I missed.Smiffy

My gen clock chip is fairly warm, but not hot.
The ICS chip is hot though, not burning hot, but could be an issue later on. I'm gonna see if i can do something about that.

I'm thinking of putting a HS on my Southbridge. On my Northbridge i've got one of those fanless Zalman chipset HS. It does the job.

At the moment i'm at FSB 200Mhz, Vmem is at 2.85v (bios).
With this voltage setting i can get up to ... 201Mhz :(

I can get higher on FSB, but need to put 2.9v & +. Would you do that?
My RAM has ramsinks (they come from a Gainward Ti4600 Golden Sample :thumbsup: ).

When the time comes (this means, extra-money and a good new board model to buy) I'll do some extra modding on this 8k3a+.

Gotta love this board, the only major flaw is the BIOS.

Never owned the 8K3A+, but i love my 8K5A3+!
What kind of modding do you have in mind?

Well to tell truth my Crucial 2700 when it was on the KR7A was getting 3.05v shoved up it.(Got it to 195Mhz.Still working now.Tried it in the other 8K3A,no problem.The Twinmoss in the 8RDA+ is at 2.9v.Maybe above 2.8-2.9v it shortens it life,but by how much.Probably be obsolete before I kill it.My Samsung 2700 throws a wobbly at anything over 2.7v.I need a thermal camera like the fella here.Good job he has done there,very helpful page.
http://homepage.ntlworld.com/bubo/index.html
Smiffy

While looking about I found this
http://home.swbell.net/mneumann/cool7vrxp1.htm
Smiffy

Do you have heatsinks on any of your RAM sticks?

I guess my memory is relatively safe w/ the Ramsinks, i\'ll try setting it at 2.95v and see what it\'ll get me.

Very helpful, thanx :thumbsup:

Hi
On the crucial yes,those copper thermaltake jobbies,makes the stick quite heavy.On the twinmoss no,its cool and getting a nice supply oof cold air blown over it anyway.Only got 1 stick in at mo.seems fine at 228Mhz on 8RDA+CAS2.5 6T,2T,2T.Wish they had taken the vmem a bit higher than 2.9v.Done the VDD mod,not going to do Vmem/Vbt mod.To much like hard work.The ICS chip on the 8K3A now has a coolermaster ram sink on it and 6-7 secs is my lot before I have to take my finger off.
May read datasheet and see what voltage supply to chip reads.Smiffy

I\'ve been running 8K3A/+ and 8K5a2+ at 220 sync and more for many month; I don\'t think u guys have to worry. Just make sure your HD is cooled otherwise it may die.

I see. Since i\'m going to watercooling very soon. I need some real quiet fans to cool my HDD\'s. I think a 80mm Noiseblocker would do the job.

Here: 8k3a+ @ 198MHz FSB for about 3 months. HDDs are still alive.

Interesting fact: I was reading product specs of one of my NICs and it\'s made to support up to 40MHz PCI clock. That\'s nice huh? :D

That\'s cool. Which brand is it?

Generic card with Realtek RTL8139/810x chipset.

Product specifications:
http://www.realtek.com.tw/products/p...spx?modelid=10

Supports PCI clock 16.75MHz-40MHz
:thumbsup:

Awesome!