Nvidia 8400M GS question (SZ series)

Hi - just a quick question.

Has anyone successfully increased their BUS speed from 64bit to 128bit with minimal overclocking? If so what driver version did you accomplish this with?

Thank you!

 

It's not possible to increase bus width in the way you suggest.
Your 8400m GS has a 64 bit bus and always will.
If you need to increase your memory bandwidth then overclocking your "memory clock" would help.

For referance you can oc: core, shaders and memory clocks and nothing else.

I'd recommend using rivatuner and trying the 174.74 driver

 

The newest driver you can overclock a 8400M GS on a Sony SZ is 169.04 however feel free to try 174.74 and let us know if it overclocks.

 

Ah, I was hoping that (aside from onchip memory) the hardware was essentially the same and the bus was limited by either the graphics bios or driver.

I actually can't run 174.74. It was causing issues with other programs that I use every day. I'm running 175.80 right now. It's ok.

My main issue is that there is stuttering (at regular intervals) that appears to be caused by a bottleneck somewhere. My card only has 64MB of dedicated video ram. I've been reading some forums in search for an answer and some users are reporting that their cards use the system memory as well. I was under the impression that the 64MB in my card was dedicated and that it didn't use any shared memory. If my card does have the TurboCache feature is there any way to temporarily disable it? (to compare performance)

Here is what the drivers report:


Here is a screen shot from GPU-Z:


Any suggestions? My system memory is only 667Mhz although I'd love to put 800Mhz memory in it if the board supported it.

It's very confusing because some users are running Vista and I sometimes think they are referring to the Vista-specific term 'Total Available Graphics Memory'. I'm running XP so this shouldn't apply.

 

667MHz is plenty for you ram, 800 MHz wouldn't show much improvement without a change in mobo and cpu when montevina is released.

It seems from those pics that you have a crippled version of the 8400m gs with inly 64mb of dedicated memory. Sadly you cannot increase this

The stuttering is probly caused when your card runs out of on-board video memory and uses the ram ie. turbocache. Turbocache is only used when needed so there's no point in disabling it.

The only thing you can do is to decrease resolution or texture quality in games as these two things account for 70-80% of Vram usage in games.

Also increasing your gpu memory clocks won't show any improvement at all so only oc core and shaders.

 

Yeah, it's the motherboard that's the limiting factor. The express version only supports up to 667Mhz. The other models in the family support 800Mhz. I already have a CPU that can take advantage of the 800Mhz FSB. It's a fast car on a one lane country road.

I wasn't looking for a solution to increase the video memory. I was aware that it only had 64MB when I purchased it. It was the bus speed on the graphics card that I was interested in. Someone on the LaptopVideo2Go forums claims to have (unlocked) the bus speed from 64bit to 128bit. I was hoping someone could chime in in this regard.

Yes, that's what I thought was causing the stutter as well. I'm already running the game at the lowest resolution (640x400) with low textures (low everything in fact). While I can get 50-60fps there is an annoying stutter that completely negates any increases in performance. It's definitely choking on something and my guess was that it was the system RAM.

So at this point my question is how to disable the TurboCache feature so I can run some performance tests and confirm that it's actually the system memory that's causing the bottleneck?

 

Did you read the last post by "guest"?

What these guys are doing is incredibly stupid! They are changing registry entries so their cards read as other cards would. It's *IMPOSSIBLE* to change hardware this way, you would be better off praying for a new card from the gpu god! I hope they fry their cards lol

For reference 64bit/128 bit etc. refers to the bus WIDTH and not speed. It's physically implemented on your gpu.

What game are you trying to play?
Also look into ati's upcoming external graphics cards for a more.. healthy approach on improving your setup

 

"The stuttering (at regular intervals) that appears to be caused by a bottleneck somewhere" could be from the reason stated in the following link.

http://forum.notebookreview.com/showthread.php?t=254189

 

Yes, I'm aware that it's related to bandwidth. Aside from increasing the speed that the data travels another solution to bottlenecks is to increase the size of the road, no? I was skeptical when I first read that thread but the differences among the G86M product line are very, very slight. From a manufacturing perspective the boards *might* be the same (excluding memory). It's not the first time the same hardware has been shipped with software locks in place to fabricate the illusion of different product tiers.

Take a look at the 8400M GT for example. The specs are almost identical (same number of pixel shaders (16), same number of transitors (210), same type of memory(GDDR3 )) yet it scores almost 1000 points higher in 3DMark05. The core clock rate is only 50Mhz higher, shaders 100Mhz higher, and as far as I can tell the memory speed is the same (just the capacity changes). The biggest difference is that the 8400M GT has a 128bit bus and came with 128MB, 256MB, or 512MB of onboard memory. The 8400M GS has a 64bit bus but also came with either 64MB, 128MB, or 256MB of memory. I'm sure the added on-board memory helped with those 3dMark05 scores but I bet the biggest contributor to performance was the increased bus size.

If the hardware doesn't exist then thats it - that's as far as it will go. If, on the other hand it is a vendor software lock (my guess is bios) then it can most certainly be unlocked. The guy may have sounded crazy because he was trying to take a G86M model and change it to a G84M model. I'm talking about changes within the same family.

The last one I tried was the demo for Devil May Cry 4. It ranked my card as B. (stylish action possible ) The game doesn't matter so much as the stuttering in the context of how many fps were being displayed. The timing and intervals of the stuttering simply should not happen at 50-60fps. So it's definitely bogged down at one point. I'd first like to try running it again without the TurboCache just to see how it does. Then (if possible) I'd like to see what what happen with a 128bit bus.

I saw that thread before and took another read through it again. I don't think I have quite the same symptoms. I mentioned previously that I had problems with the 174.74 drivers with other software that I use. Microsoft has a thread discussing this problem and has identified mouse drivers (and in another post nvidia) drivers as the problem. The mouse software didn't apply to me so I started to look at the nvidia drivers. Upgrading to 175.80 solved my issue with SSMS. I haven't commented in that thread yet but in the past (on a completely different laptop) the ALPS touchpad has been responsible for symptoms similar to what they are describing.

 

Sorry i wasn't clear enough again. The bus width refers to how many bit's wide the bus physically is, NOTHING to do with bandwidth. It's true some models have shader piplines blocked or cut but yours being one of those is extremely unlikely. Increasing your memory clock increases bandwidth as would a bigger bus but since you have only 64mb on board memory more bandwidth would be *absolutely* useless!

If you really want to improve your card the try following one of the overclocking guides and oc your core an shaders but thats ALL you can do.