Quick Hypertransport question

idont

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Apr 23, 2008
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Hello,

I decided to OC my Athlon X2 4800+. I'm an absolute beginner with overclocking but after reading a lot, I think I know how it all works. As a starter, I decided to OC my CPU by 100MHz. Now CPU-Z reported me a Hypertransport speed of about 1100MHz. I've read on some forums to don't let it go above 1GHz.

My question is: is this obselete or does this 1GHz rule still apply?
And the second question: I got a HT 3.0 motherboard, which can handle 2.6GHz according to the specs. Even though you may want to keep the HT speed around 1GHz, is it safe to run speeds between 1000MHz and 2600MHz on a HT 3.0 bus?

Thanks in advance,
-iDont

btw I know that I can keep the HT speed around 1Ghz by lowering the multiplier, but these questions are more for my knowledge.
 

closed_deal

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You have a question that i haven't seen yet which is quite nice to see :).

When I was an AMD owner with a mobo that supported only 1000Mhz HT it acted as a sort of barrier, which would have to be knocked down everytime i'd get another 100Mhz on the total clock speed.

Which leads me to think that if your mobo supports HT 3.0 which it does then the higher HT will allow you to overclock more before you have to lower HT again :). I think the best way to find out for sure would be to let yours get has high as it can before it won't POST via instability.

It'll be interesting what you find...

As for how high HT can go I had mine quite high perfectly stable, just had to increase the HT voltage a tad. : http://valid.x86-secret.com/show_oc.php?id=282771
 

idont

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Thanks for your reply.
I'm new at overclocking and I don't want to overclock that much, so I'll probably don't get high HT speeds.

As for now I got this:
Bus speed: 250 MHz (default 200)
Multiplier x11.0 (default 12.5)
Raised the voltage with 0.025v, otherwise the Windows would freeze
So that gives my Athlon 4800+ (Brisbane 65nm btw) a stunning 2,75GHz :p
A 10% overclock is enough for today, maybe I'll go on later.

With HT set to 1GHz (x5) I got the HT bus to run at (250x5) 1250MHz and it ran stable
but just to be on the safe side I've set the HT bus to 800MHz (x4) so it'll run at (250x4) 1GHz, stable too

If you want to know, I got an AMD 770 Northbridge & SB600 Southbridge

Now I got another quick question, which shouldn't belong here but doesn't deserves a whole new thread:
With my new multiplier and bus speeds my RAM got up to ~458MHz (with 4-4-4-15 timings). It is OCZ Platinum DDR2-800 Rev.2 memory designed to run at 400mhz 4-4-4-15 timings. Would I need to increase the default voltage (2.0v)? With the overclock (458MHz) at 2.0v it survived 30minutes Prime95 blend test with no errors.

-iDont

 

closed_deal

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Nice first days o/c :D.

I would say if you can get over 20 minutes Prime95/Orthos with your RAM at 4-4-4-15 @ 458Mhz your RAM will be stable. Many ppl like to stress their comps for as long as they intend to use them avg 7-8 hours.

You can increase the voltage to make it stable (recommended max is 0.2v over manufac's max). But, if your running stable there is no need to increase the voltage any further.

You will hit a FSB wall soon mind. Then either the RAM mhz will have to be dropped or the timings relaxed to 5-5-5-15.

How high will you get tomorrow :)?

Here's a challege ----> http://www.pcstats.com/articleview.cfm?articleid=1845&page=2
 

idont

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Thanks! I've ran Prime95 for some additional hours and everything went fine.
Other things I've done is making my PC a bit more silent, I've set the CPU fan to a 1500RPM limit, keeping my CPU around 50 degrees at 100% load (Rear (exhaust) fan set to ~1100RPM, Side fan (25cm) set to 450RPM and the front fan (intake), well that darn fan is always runnin at 100% :p)


I'm happy with the new speeds, I'm not a die-hard overclocker, I just wanted a bit more speed while staying on the safe side which I can use 24/7 so I'll probably let it on 2,75GHz for a while.

But this all goes a bit off topic as my question is already awnsered, so I'll leave the topic now as it is.

-iDont
 

coa

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Increasing HT over 1000 will definitely crash your system for some time.Get multi to 4x and HT on 1000MHz and that is OK.

PS Why are you decreasing multi?The higher the multi is more MHz you will get.Get it back to 12.5x and bus speed(how you call it) to 220 and you will get same clock with less power and without changing voltage.Than set bus speed to 250 and you will get 3.125GHz!!!Increase a voltage for about 0.1V and it will be stable probably.Got it?

PS(2) Good first day :)
 

Verillion

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I have seen outdated articles that state don't go over 1000mhz on your HT, but I have not read anything recent supporting that claim. Also, I have personally run my Hypertransport up to 1.5ghz and not had any stability issues, although you don't get any performance gains either.

I have heard risks of data corruption at HT speeds over 1100mhz, but then again, never experienced those problems.