NVIDIA's shady trick to boost the GeForce 9600GT

[DilTech]

actually, there's no problem in bringing to the average Joe an auto-overclocking and dummyproof performance increase
what makes it a cheat and a **** is:
- it's not documented/advertised by nvidia
- the driver reports the non-overclocked frequency
so basically looks like nvidia wants to hide this and make people think their cards at stock frequencies are faster then they actually are.

The same average joe you speak of wouldn't know how to check the driver for the non-overclocked frequency in the first place. Also, linkboost IS an advertised feature, this is just the first card to truly take advantage of the increased PCI-E frequency.

Finally, stock is stock. You take your card, pull it out of the box, put it in your computer and run it? That's stock. All this means is, stock speed on a NVidia chipset is different than stock speed on a different chipset.

Personally, I really like the idea of the new feature, as I'm sure a lot of people here will.

I do want to know one thing though.....

Why doesn't the guru3d testing show the same issue?. Guru3d use rivatuner in their sli review of the 9600GT to show temps(page 4 of the review), which is done on a 680i. The inno3d card is still at 700mhz, using the same tool tech powerup said showed the issue.... So can someone explain what's going on here with this?

[hollo]

I can confirm this,
I have a p35 chipset and my card can play ingame at 820Mhz stable on the stock cooler - cheap zotac card

hmm, then there's factory overclocked cards... eg the card used in the techreport article had a default clock of 725.
if they put it in a linkboost board, 725 * 125/100 = 906.25mhz = crash?

[Jowy Atreides]

hmm, then there's factory overclocked cards... eg the card used in the techreport article had a default clock of 725.
if they SLI'd it in a linkboost board, 725 * 125/100 = 906.25mhz = crash?

admittedly my card is factory clocked at 675 Mhz

[Luka_Aveiro]

I can confirm this,
I have a p35 chipset and my card can play ingame at 820Mhz stable on the stock cooler - cheap zotac card

Auto overclocked by linkboost or manually overclocked?

[Tuvok-LuR-]

Also, linkboost IS an advertised feature, this is just the first card to truly take advantage of the increased PCI-E frequency.

It does not take advantage of the increased PCI-E frequency, it takes advantage of the increased GPU frequency

Finally, stock is stock. You take your card, pull it out of the box, put it in your computer and run it? That's stock. All this means is, stock speed on a NVidia chipset is different than stock speed on a different chipset.

So that's not shady at all?
The point is, if nobody would have spotted this thing:
average joe goes on the web, looks for vgas benches, finds a 9600gt bench on 680i with linkboost enabled, thinks, wow, that card is fast!
Average Joe buys a 9600gt for his P35 mobo.
Average Joe PC will perform lower than what he thought

[Tuvok-LuR-]

Auto overclocked by linkboost or manually overclocked?

linkboost is nv mobos only feature

[Frank M]

Allot of folks by oc'd cards and pay extra for them, this is basically no different other than not paying extra for an oc edition card.

It's free performance so I don't personally see anything wrong or shady about it.

How's about having it reviewed on nv chipset boards, and forgetting to
mention that it only does so well on their chipsets, but on others, that
speed advantage is gone?


IMO techreport should've made a test: performance on nv and performance
on non-nv chipsets. It would be much better proof, these are just theories.

[hollo]

remember, linkboost is only for SLI
edit: my bad, it's automatic on all link-boost enabled chipset and gfx card combinations

a feature that overclocks SLI setups (more than just the PCI-e bandwidth, which does basically nothing) is bad enough, if nVidia made a feature that overclocked single nVidia GPUs on nVidia chipsets they'd get teh rape from the tech-press

[Jowy Atreides]

Auto overclocked by linkboost or manually overclocked?

manually clocked by the manufacturer,
gpu-z reads 675 as default

[Luka_Aveiro]

manually clocked by the manufacturer,
gpu-z reads 675 as default

And the hardware monitor in rivatuner, your readings are...?



This is the basis of TechPowerUP theory, it could just be a reading error, afaik.

[metro.cl]

It does not take advantage of the increased PCI-E frequency, it takes advantage of the increased GPU frequency


So that's not shady at all?
The point is, if nobody would have spotted this thing:
average joe goes on the web, looks for vgas benches, finds a 9600gt bench on 680i with linkboost enabled, thinks, wow, that card is fast!
Average Joe buys a 9600gt for his P35 mobo.
Average Joe PC will perform lower than what he thought

Since when you can run SLI on P35? and if average Joe look for SLI benchs to buy a Single card, he did it wrong.

I like this you get more performance for you $$$ out of the box, every guy that has seen a review saw it on nf680i or nvidia chipset and if they want to use this they have to buy a nf680i so they will get the boost. If they want single card they wont get it as linkboost only works on SLI.

It is still nice to know about this feature, also does everycard out there do this?

[metro.cl]

And the hardware monitor in rivatuner, your readings are...?



This is the basis of TechPowerUP theory, it could just be a reading error, afaik.

That always happends, and is because clock speeds arent linearly selectable, they have jumps, if this is all the basis of TPU review means they havent messed with cards in a long time.

[DilTech]

I guess no one read my post pointing out that guru3d shows the readings off of rivatuner, and nothing out of the ordinary showed up on their testing.

[Tuvok-LuR-]

That always happends, and is because clock speeds arent linearly selectable, they have jumps, if this is all the basis of TPU review means they havent messed with cards in a long time.

I think that who wrote that stuff actually knew what he was talking about, and also
"Acknowledgments: I would like to thank Unwinder and Sampsa for their great input and discussions on this topic."

[Tuvok-LuR-]

remember, linkboost is only for SLI

Since when you can run SLI on P35? and if average Joe look for SLI benchs to buy a Single card, he did it wrong.

Linkboost works also in single card mode

[STaRGaZeR]

Why doesn't the guru3d testing show the same issue?. Guru3d use rivatuner in their sli review of the 9600GT to show temps(page 4 of the review), which is done on a 680i. The inno3d card is still at 700mhz, using the same tool tech powerup said showed the issue.... So can someone explain what's going on here with this?

Mainboard

nVIDIA nForce 680i SLI (eVGA)

What a coincidence it is that some NVIDIA chipsets offer a feature called "LinkBoost" that automagically increases the PCI-Express clocks. This feature was pioneered with the NVIDIA 590i chipset and is present in the NVIDIA 680i chipset too, but has recently been disabled as far as I know.

You'll have to ask Guru3D to know if they have LinkBoost enabled or disabled, or if they have a BIOS that automatically enables or disables it.

This "feature" is very good for overclocking noobs.

But it's a VERY BAD marketing procedure, not telling the reviewers about it, increasing the scores WITHOUT even know it, looks like the card is much better than it really is. You can't review a card saying that its clocks are X, which in fact are X+something due to LinkBoost or the reviewer manually increasing PCI-E frequency on any other chipset, overclocking the card and showing overcloked results. So, again, NVIDIA for another lamentable marketing move.

But this time we have caught you

[hollo]

Linkboost works also in single card mode

oh yeah true, the link-boost diagrams always show SLI setups, but the product description says it'll do it automatically for any link-boost enabled card

[Luka_Aveiro]

Guys, you haven't realized yet this has nothing to do with linkboost...

It has to do with PCI-Express frequency, once techpowerup considers PCI-Express frequency/4 is the clock generator for gpu frequency, as 100mhz/4=25mhz, that should be a regular crystal clock generator, but that doesn't exist on the 9600GT!!!!

When looking at the PCB, the only crystal we could find is a 27 MHz one, so where is the magical 25 MHz coming from ?

As many of you know, the PCI-Express bus clock frequency which connects the card to the rest of the system is running at 100 MHz by default. What NVIDIA did is to take this frequency and divide it by four to get their reference frequency for the core clock.

On systems where the PCI-E bus runs at 100 MHz, this results in the 25 MHz used for the default clock indeed. But once the PCI-E clock is increased beyond that, the GPU will magically run at higher clock speeds, without any changes to the graphics configuration, BIOS, driver or any software.

On "normal" VGA cards, when you increase the PCI-Express bus frequency you increase the theoretical bandwidth available between card and the rest of the system, but do not affect the speed the card is running at. On the GeForce 9600 GT, a 10% increase in PCI-Express frequency will make the card's core clock run 10% faster!

So, taking their example: 725mhz/25mhz(clock generator powered by pci-express@100mhz)=x29;
If PCI-Express Frequency= 110mhz-> 110:4=27,5; 27,5x29= ~798mhz

Let's take it to stock clocks:
650/(100/4=25)=x26
(110/4)=27,5; 27,5x26=715mhz

So, 715-650=65; 65=10% of 650
So if you increase PCI-Express by 10%, you will increase your core clocks by 10%.

I wish I had a 9600GT in my hands to confirm this, it just seems too good to be true

[hollo]

Guys, you haven't realized yet this has nothing to do with linkboost...

It has to do with PCI-Express frequency,

well, linkboost bumps the PCI-e frequency from 100 to 125mhz on certain nvidia chipset/gfx card combinations, and since very few people change their PCI-e frequency that's the only way this could be much more than trivia

and since a 25% overclock would crash a lot of 9600 GTs, not to mention that it would be widely interpreted as nvidia 'cheating' to make their chipsets look better, i'd bet the 9600 GT isn't linkboost enabled

or it is linkboost enabled, but the card automatically changes the ratio so the new PCI-e frequency is accounted for
eg
normal = 100mhz/4 * 26 = 650mhz
linkboost = 125mhz/5 * 26 = 650mhz

[ToTTenTranz]

So the card automatically overclocks.

If it doesn't affect stability, it's great.

If it does, even if a little bit, then nVidia should pay for it. Hard.

[wittekakker]

I guess it's all true guys. I have been running 9600GT's clocked at 720MHz out of the box, but the card never remained stable in my tests. I got in another sample, same happened. Now, due to rushing things, I have left my sources wondering what the problem could be, but now it all seems to come down to the simple fact where my PCIe bus speed could have been the problem all the time. I have it overclocked to 110MHz all the time which makes the GPU run at 780MHz instead of 720MHz, downclocking the GPU solved it so I guess PCIe speed did affect card clocks. Makes sense, I really don't know why else my three samples couldn't clock further then 710MHz with 110MHz PCIe speed.


I have an Intel X38 chipset. Those wondering if it will work on any chipset, please spend some time reading the article. It counts only 4 pages and you will not have to spend time posting 10 times here on XS in order to find out. It is based on PCIe speed, nothing to due with Linkboost instead that Linkboost will now overclock your VGA GPU too further increasing the total system performance.

[Luka_Aveiro]

I have it overclocked to 110MHz all the time which makes the GPU run at 780MHz instead of 720MHz, downclocking the GPU solved it so I guess PCIe speed did affect card clocks. Makes sense, I really don't know why else my three samples couldn't clock further then 710MHz with 110MHz PCIe speed.

FIY, if you had your PCI-Express frequency defined as 110mhz and you wanted to run GPU at 720mhz, it should have been running at 720x1,10= 792mhz not 780... What programs did you use for readings?

Man I'm so excited with this that I really want a 9600GT NOW!

Do you realize with extreme cooling/voltage we could easily achieve past 1GHZ frequency?

THIS IS A MAJOR TWEAK!

[saaya]

lame! thanks for making this public!

[Cybercat]

I've not heard of a card that uses a 25MHz multiplier anyway. They all use 27/54MHz multiples.

[ToTTenTranz]

Do you realize with extreme cooling/voltage we could easily achieve past 1GHZ frequency?

THIS IS A MAJOR TWEAK!

If you still need extreme cooling/voltage to achieve 1Ghz+ frequency, why is pci-e based overclocking a "MAJOR TWEAK"?
On some mobos, increasing the pci-e frequency even causes the hard drives to malfunction.