Why does ATI limit overclocks and Nvidia do not.

[Mr Krugga]

Well I guess ultimately, it means ATI's vendors can sell pre-overclocked cards for inflated prices because typical users are unable to get round the soft limit.

Typical users don't overclock.

 

[Jokester]

Nvidia GTX 460 - max voltage allowed 1.087v
ATI HD 5000 - max voltage allowed = 1.35v.

ATI HD 5770 / 5850 / 5870 on air - around 1000 Mhz easilly possible out of the box with an unlocked version (MSI or Asus).

Nvidia GTX 460 - Around 800 - 900 Mhz possible out of the box, and to reach the higher limits you have to get a really lucky chip.

I have to disagree, you dont get anywhere near enough leeway with Nvidias stock limits, and ATIs limits are nowhere near as drastic as Nvidias are (providing that you buy a pre unlocked version, which is what you should do if you plan to overclock).

You can't compare them like that, as the chip designs are totally different. It would be better to compare typical overclocks as a percentage.

 

[Mr Krugga]

Most 5850s do 900MHz with voltage increase to 1.15V. That is less than 6% voltage increase for over 24% overclock.

 

[RavenXXX2]

Why compare two cards why not compare the whole line up? Also to your question im pretty sure they dont want people to blow the arse out of their card with an included oc'ing tool

Feel free to compare if you want but I believe all the mid/highend stand ATI cards are limited in the bios to how far you can clock, usually you can have a free 50Mhz that would be on the 5770/5850/5870. From all the nvidia based forums, the 460/465/470/480 have a max limit that you would not realistically expect to achieve through standard air or watercooling.

 

[bhavv]

You can't compare them like that, as the chip designs are totally different. It would be better to compare typical overclocks as a percentage.

Indeed, in that case, the ATIs still win because just about all of them reach 1000 Mhz, whereas getting the GTX 460 past 850 Mhz is based on luck.

Typical users don't overclock.

Conclusion - for the normal user who doesnt overclock, any brand is fine.

To the enthusiast that wants to overclock, buy an Asus or MSI.

/end thread.

I could have bios modded my MSIs by now, but I dont want to void the warranty on them this time because they are still covered while clocked to 890 Mhz, unlke my previous sapphires.

 

[Jokester]

Typical users don't overclock.

Plenty of non-technical people will use the built in overclock tool, far far more than those who will bother to circumnavigate the soft lock.

 

[Jayster]

Feel free to compare if you want but I believe all the mid/highend stand ATI cards are limited in the bios to how far you can clock, usually you can have a free 50Mhz that would be on the 5770/5850/5870. From all the nvidia based forums, the 460/465/470/480 have a max limit that you would not realistically expect to achieve through standard air or watercooling.

I can do an extra 110Mhz on my 5770 on overdrive and go past that with afterburner without having to touch the bios.

 

[Mr Krugga]

Plenty of non-technical people will use the built in overclock tool, far far more than those who will bother to circumnavigate the soft lock.

That's why ATI (or not ATI but vendors) will limit this tool to avoid a flood of RMAs. There's a simple rule, if you can't overclock, don't.

 

[Alsedo]

I can overclock my 5850 to 875/1225 using CCC. It's not a reference card, so maybe that makes a difference. I haven't modded the BIOS and use stock voltages.

I don't use MSI Afterburner as the UAC prompt on startup is annoying and I'm happy with my 20% overclock anyway.

 

[Jayster]

Its xfx but its the normal reference design one.

 

[bhavv]

Not too sure on the 5770, is the XFX a pre-overclocked model? it maybe that is what the limit is on the 5770.

The stock limit on the 5770 is 960 Mhz. The cards still barely reach 70 degrees when clocked to that much.

 

[Jokester]

Indeed, in that case, the ATIs still win because just about all of them reach 1000 Mhz, whereas getting the GTX 460 past 850 Mhz is based on luck.

Locked 5870 - 850 > 900 MHz = 6%

460 - 675 > 800 = 19%

 

[Jokester]

That's why ATI (or not ATI but vendors) will limit this tool to avoid a flood of RMAs. There's a simple rule, if you can't overclock, don't.

But they then sell an identical card, at a higher price, with higher clocks.

 

[RavenXXX2]

The stock limit on the 5770 is 960 Mhz. The cards still barely reach 70 degrees when clocked to that much.

Yeah they come stock at 850Mhz so an extra 110, I wouldn't expect them to generate much more heat with a 960 core.

 

[Mr Krugga]

But they then sell an identical card, at a higher price, with higher clocks.

And EVGA sells the same cards as other vendors at much higher price tag - with longer warranty. What's wrong with that? GeForce 480 costs £125 more than 470, 5870 costs £80 more than a little slower 5850. It's business, you milk a cow you own.

 

[Jayster]

Yeah they come stock at 850Mhz so an extra 110, I wouldn't expect them to generate much more heat with a 960 core.

Once you go over 950 they start but 850 to 950 there is maybe a 1-2 degree difference on air for my card anyway Its a very efficient chip.

 

[drunkenmaster]

Can someone please explain why ATI very much limit the overclock potential of their cards via the bios, and why does Nvidia not hold back the overclocking potential on their cards via the bios?

Example, all 5870's apart from specialist brands like Asus and MSI have their overclocks limited to 900Mhz which is a measly 50Mhz over the stock clocks.

5850's are worse, these great clocking cards are limited to 775 core through the bios.

Now I know of no recent Nvidia cards that limit overclocks to such low clocks, if there is please point them out.

Can you explain how this wasn't a problem before you got an Nvidia card, or how its not a problem when you use afterburner to overclock and not the Nvidia control panel, and afterburner simply has a function to lock to the warranty covered overclocks, and has an option to ignore that.

Get it right, with Nvidia, overclock 1Mhz and you're not officially covered by warranty, nor will they say your card will be stable.

AMD allows you to overclock up to the limits in overdrive, it essentially says "this is what your card is stable at with shipping voltage at least, all cards will do this, we're very happy for you to overclock to this point".

LIkewise any card maker is quite free to apply whatever limits they want in the bios, Asus and lots of other cards now come with far larger bios limits.

For decades there was no overclocking within the Nvidia control panel, you had to use the "coolbits" registry change to enable clock control at all.


As said there is NO LOCK at all to stop unlimited overclocking, otherwise no card would go beyond those limits you see in overdrive.

The overdrive limit is just that, what their driver will allow as a "safe" overclock that will not void your warranty. My 5850, locked in overdrive to 775, runs along happily at 1050Mhz, because there is no lock in the bios to prevent overclocking fullstop.

 

[Jokester]

And EVGA sells the same cards as other vendors at much higher price tag - with longer warranty. What's wrong with that? GeForce 480 costs £125 more than 470, 5870 costs £80 more than a little slower 5850. It's business, you milk a cow you own.

There's nothing wrong with it, I'm just pointing out one reason why ATI cards have the soft lock on overclocking

 

[drunkenmaster]

Locked 5870 - 850 > 900 MHz = 6%

460 - 675 > 800 = 19%

My "locked" 5850 goes from 725 to 1050Mhz, yup, 45%, I really should move to a 460gtx that will be around 50% slower at 1920x1080 with 4/8xaa, because its unlocked and therefore will clearly overclock further.

 

[RavenXXX2]

The overdrive limit is just that, what their driver will allow as a "safe" overclock that will not void your warranty. My 5850, locked in overdrive to 775, runs along happily at 1050Mhz, because there is no lock in the bios to prevent overclocking fullstop.

Open up your cards bios in http://www.techpowerup.com/downloads/1770/TechPowerUp_Radeon_Bios_Editor_v1.25.html and see what clocks your card is limited to. Regarding warranty, lets face it they will never know if the card has been clocked or not, even if it was true why do nvidia not limit overclocks.