# How to disable turbocache?



## beefers1 (Aug 23, 2007)

i have an 8400GS, and i think the default setting for turbocache is on. is there any way to disable it? i don't do any graphics-intensive work, and windows says that i only have 2.75GB of RAM installed, but i'd rather have my ram for the main processing unit. thanks


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## beefers1 (Aug 23, 2007)

hello? anyone have a possible solution?


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## beefers1 (Aug 23, 2007)

No one? it's been a week and a half, is everyone here on vacation or something?


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## UncleMacro (Jan 26, 2005)

> No one? it's been a week and a half, is everyone here on vacation or something?


Some things are sufficiently obscure that hardly anyone knows how to do it. And yes, people here do go on vacation.

I haven't done it myself but if you're running Windows XP (this may not work in Vista) then you can disable TurboCache using RivaTuner.


Download RivaTuner from here and install it.
Run RivaTuner and go to the "Power User" tab.
Find the entry which says "NVIDIA Forceware (version) (os) System".
Click the "+" to the left of the "NVIDIA Forceware (version) (os) System" entry to display the list of values.
Find the "RMDisableRenderToSysmem" entry and set its value to 1.
Close Rivatuner and reboot.

If all is well then the amount of video RAM reported by Windows should go down to the amount of physical video RAM on the card. There are some screenshots on this page.


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## beefers1 (Aug 23, 2007)

i tried that, and system still reported 2.75GB RAM and 512MB VRAM (though there're only 256 megabytes of dedicated video memory). what does RMdisableRenderToSystem mean anyway?


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## UncleMacro (Jan 26, 2005)

RMDisableRenderToSystem is the only way I've heard of to do it. A video driver has about a zillion configuration switches in the registry. Setting switch values is how you configure the driver. RMDisableRenderToSystem presumably does what it sounds like: disables rendering to system (motherboard) memory. That means it would render (draw) only in video RAM on the video card.

If it's ignoring the switch then I'd try updating the to latest display driver to make sure it supports the switch. These registry switches are "internal" configuration controls and change from driver to driver. You could also google around for someone succeeding with RMDisableRendToSystem on an 8400 GS and see which driver version they're running and then install that driver on your machine.

If that doesn't work then I'd spend some time in google and see if there's another more obscure way to do it. But generally they just have a registry switch to control this sort of thing. RMDisableRenderToSystem is the only one I've heard of which affects it.


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## beefers1 (Aug 23, 2007)

oh, and this brings up something. i read somewhere in a magazine article (i think PCMag) that i can tweak my video settings with nTune. But when i double-clicked on it, it wouldn't open. is double-clicking the .exe the correct way to open it?


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## UncleMacro (Jan 26, 2005)

I'm afraid it's been a while since I've run nTune but I don't remember anything weird about installing or running it so I assume it was just like any other program.

Most people don't use nTune because many of its features depend on motherboard BIOS support and most motherboards don't support nTune very well. If you're fiddling with a video card It's better to stick with something which is used by the serious overclockers like RivaTuner. They make sure it's up to date and works with various driver versions. For most of the standard configuration stuff all programs are just setting the same registry keys anyway so it's best to stick with the one which is used to the most.


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## beefers1 (Aug 23, 2007)

i see. i just overclocked my CPU, but that was through the setup screen at startup. it's now running at 2.61GHz. any higher, and it made the system unstable. anyway, back to the point. so i suppose there really isn't any obvious solution? also: you have a 160MB hard drive? and a 200MB? how did you manage to install XP?


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## UncleMacro (Jan 26, 2005)

> you have a 160MB hard drive? and a 200MB? how did you manage to install XP?


Oops! Awww... megabytes; gigabytes; what's the difference?



> i see. i just overclocked my CPU, but that was through the setup screen at startup. it's now running at 2.61GHz. any higher, and it made the system unstable.


Yea. My CPU is actually a 2.8 GHz and I overclocked it to 3.2 GHz from the BIOS. Personally, I overclock motherboard functions from the motherboard BIOS only rather that use a Windows program. That way I know there's no compatibility problems. And I use ATITool (a Windows program) to fiddle with my Radeon 9700.



> anyway, back to the point. so i suppose there really isn't any obvious solution?


I've just googled around and I couldn't find any other registry keys which controlled TurboCache. I did, unfortunately, find a number of people with 8X00 NVIDIA cards who said the RMDisableRenderToSystem key didn't work for them and I didn't see anyone with 8X00 cards who reported that it worked (although they don't tend to post as much as the people who have problems). It looks like that key is now outdated and only worked with older 6X00 and 7X00 cards. Spending a few hours searching might find another approach but I didn't see any in 15 minutes worth of checking.


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## beefers1 (Aug 23, 2007)

dang. ok, well thanks anyway. I'll keep looking around. also: i tried OC'ing to 2.66, which was the Q6700's stock speed, but after booting up (which went amazingly fast) everything was really "twitchy" and unstable. and that was from the BIOS. but i found nothing in there that let me configure video card settings.


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## UncleMacro (Jan 26, 2005)

> but i found nothing in there that let me configure video card settings.


The motherboard BIOS can only configure the motherboard oriented things related to video cards like AGP speed, PCI-Express things, etc. Things like TurboCache are strictly video card functions which the motherboard knows nothing about so those kinds of settings are done with Windows programs only.


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## beefers1 (Aug 23, 2007)

I see. well, thanks. I'll let you know if i find anything useful


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## zark0g (Apr 5, 2008)

instead of RIVA you can simply enter registry |

HKLM/SYSTEM/CURRENTCO..../CONTROL/VIDEO/[ure vga drivers -- just click on each till you find a long list of driver strings -- there are plenty(beaware if you have onboard gfx and have had other gfx cards with different drivers -- your choice must be specific to the turbocache driver]/0000/RmDisableRenderToSysMem 
this binary value RMDISABLE... is what you need. change the value to 01 00 00 00

if there is no BV there

create it -- right click /new/binaryvalue ... ignore the standard 0000 it gives you, they cant be changed and type the name RmDisableRenderToSysmem and the value 01 00 00 00.

reboot-- fingers crossed you dont blow up your computer. E' voila -- vga card memory only.

Shouldnt really matter what operating system you have or driver set.


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## beefers1 (Aug 23, 2007)

zark0g said:


> fingers crossed you dont blow up your computer.


you don't sound too confident.... are you sure about this?


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## UncleMacro (Jan 26, 2005)

The whole point of running RivaTuner is to avoid manually editting the registry in the first place. Programs like RivaTuner do exactly what zark0g is suggesting but provide simple, debugged code which keeps people from hosing their registries. It's just code in RivaTuner diddling the registry keys rather than a human doing the exact same thing manually.

If that key isn't working for your video card with RivaTuner then it won't work any better manually. I'm not 100% sure about this case but the problem is likely caused by newer drivers which don't support the key anymore. NVIDIA and ATI change those keys and programs like RivaTuner have to be changed to keep up. And if NVIDIA no longer provides a registry key for that functionality then there's nothing you can do about it.


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## beefers1 (Aug 23, 2007)

oh. crap. well, thanks anyway.


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