> Surely that's a rather rare failure mode on a graphics card?

About the same as getting some bad RAM bits in your normal PC RAM probably.

> That seems to me more like the kind of thing where you get a brand new 
> card and it's DOA. This card has been installed and running without issue 
> for years.

I had the RAM in my desktop machine at work partially fail after some time. 
It started when dealing with big zip files, it would complain that the CRC 
check didn't match up, even though I had just downloaded it.  Then it would 
blue-screen randomly, and gradually got more frequent.  I did the memcheck86 
or whatever it was and there was an area of RAM that was totally corrupt, 
it's a wonder Windows even booted, let alone worked normally most of the 
time.  Replaced the RAM and very reliable now.

I had the same with my nVidia Ti4200 graphics card, actually identical 
symptoms to you, random triangles flickering across the screen.  Gradually 
got worse over time, and also while playing a game until it crashed.  Tried 
it in my sisters PC and the same symptoms.  I didn't bother trying to figure 
out the cause, but just assumed it was bad RAM.

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>> Surely that's a rather rare failure mode on a graphics card?
> 
> About the same as getting some bad RAM bits in your normal PC RAM probably.

Well, you'd think. ;-)

I've bought brand new RAM sticks to find that they're defective, and 
I've occasionally damaged one inserting or removing it, but never seen 
one just fail during normal use. They seem to be quite reliable.

> I had the RAM in my desktop machine at work partially fail after some 
> time. It started when dealing with big zip files, it would complain that 
> the CRC check didn't match up, even though I had just downloaded it.  
> Then it would blue-screen randomly, and gradually got more frequent.  I 
> did the memcheck86 or whatever it was and there was an area of RAM that 
> was totally corrupt, it's a wonder Windows even booted, let alone worked 
> normally most of the time.  Replaced the RAM and very reliable now.

Yeah, RAM failures cause weird crap to happen. Depending on where in RAM 
the problem is, it often only causes problems when you try to do certain 
things. (But what with virtual memory, it's quite hard to predict when 
it will or won't show up a problem.) Diagnosing RAM faults without a 
real RAM tester is just Not Fun...

> I had the same with my nVidia Ti4200 graphics card, actually identical 
> symptoms to you, random triangles flickering across the screen.  
> Gradually got worse over time, and also while playing a game until it 
> crashed.  Tried it in my sisters PC and the same symptoms.  I didn't 
> bother trying to figure out the cause, but just assumed it was bad RAM.

Well, since the RAM isn't replaceable on a graphics card, I guess it 
really just boils down to "does this graphics card work properly or not?"

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On Mon, 18 Aug 2008 15:43:22 +0200, Invisible <voi### [at] devnull> wrote:
>>  4. Hardware fault on the graphics card (eg bad RAM)
>
> Surely that's a rather rare failure mode on a graphics card?

Not if it has been overheating.





Have you checked the temperature of the video RAM?



-- 
FE

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>>>  4. Hardware fault on the graphics card (eg bad RAM)
>>
>> Surely that's a rather rare failure mode on a graphics card?
> 
> Not if it has been overheating.

True, but since the GPU generates far more heat than a block of RAM does...



> 
> Have you checked the temperature of the video RAM?

I don't have a way to do that.

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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On Mon, 18 Aug 2008 17:25:30 +0200, Invisible <voi### [at] devnull> wrote:
>>>>  4. Hardware fault on the graphics card (eg bad RAM)
>>>
>>> Surely that's a rather rare failure mode on a graphics card?
>>  Not if it has been overheating.
>
> True, but since the GPU generates far more heat than a block of RAM  
> does...

The GPU also has far better cooling. Modern high-performance RAM can get  
rather hot, particularly video RAM.





>>  Have you checked the temperature of the video RAM?
>
> I don't have a way to do that.

Try touching a VRAM chip (very briefly) while the game is running.



-- 
FE

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>> True, but since the GPU generates far more heat than a block of RAM 
>> does...
> 
> The GPU also has far better cooling. Modern high-performance RAM can get 
> rather hot, particularly video RAM.

Well, if they don't bother fitting cooling to a component, that 
presumably means they don't think it's necessary. ;-)

> Try touching a VRAM chip (very briefly) while the game is running.

Wouldn't simply having the case open radically alter the operating 
temperature of the components inside? ;-)

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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scott wrote:
> Actual chip core temperature of 55 degrees seems fine to me,

Compare it to your CPU temperature. I dunno about my GPU, but my CPU is 
close to 55 just sitting idle.


-- 
Darren New / San Diego, CA, USA (PST)

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On Mon, 18 Aug 2008 17:39:57 +0200, Invisible <voi### [at] devnull> wrote:
>>> True, but since the GPU generates far more heat than a block of RAM  
>>> does...
>>  The GPU also has far better cooling. Modern high-performance RAM can  
>> get rather hot, particularly video RAM.
>
> Well, if they don't bother fitting cooling to a component, that  
> presumably means they don't think it's necessary. ;-)

It can also mean that they chose not to include VRAM coolers because it is  
cheaper that way. Whether they are necessary or not depends on many  
factors outside the control of video card designers. Also, simply having a  
cooler is not the same as having an effective cooler.



>> Try touching a VRAM chip (very briefly) while the game is running.
>
> Wouldn't simply having the case open radically alter the operating  
> temperature of the components inside? ;-)

It can change the temperature, but not radically, unless you are talking  
about the video card casing. In any event I doubt you could get an  
accurate temperature reading using only your fingertip under any  
circumstances. The point of the exercise is simply to get a feel for how  
hot those things get.


-- 
FE

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>> Actual chip core temperature of 55 degrees seems fine to me,
> 
> Compare it to your CPU temperature. I dunno about my GPU, but my CPU is 
> close to 55 just sitting idle.



-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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>>> Try touching a VRAM chip (very briefly) while the game is running.
>>
>> Wouldn't simply having the case open radically alter the operating 
>> temperature of the components inside? ;-)
> 
> It can change the temperature, but not radically, unless you are talking 
> about the video card casing. In any event I doubt you could get an 
> accurate temperature reading using only your fingertip under any 
> circumstances. The point of the exercise is simply to get a feel for how 
> hot those things get.

Ooo... Maybe I should use my IR thermometer? :-D

-- 
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*

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