Πρόβλημα με OpenGL

[capthookb]

Τελικά έφταιγε το agp aperture size από το bios. Για κάποιο λόγο είχε πέσει στη μικρότερη τιμή του, νομίζω 4mb (ίσως έχει πέσει η μπαταρία της μητρικής μου).

Αυτό που ήξερα μέχρι τώρα ήταν πως το aperture size ήταν η ποσότητα μνήμης την οποία χρησιμοποιεί η κάρτα γραφικών όταν τελειώσει η δική της. Όμως κάτι τέτοιο δεν ισχύει. Αν κατάλαβα καλά είναι το "παράθυρο" μέσα από το οποίο μεταφέρονται δεδομένα στην κάρτα γραφικών και γι'αυτό είχα πρόβλημα στην περίπτωσή μου.

 

 

"The AGP Aperture Size is the amount of system memory for the

AGP card, so host cycles hitting that area are forwarded to that

card without translation..."

 

This may be causing confusion because it really should read

"amount of system address space". Too many writers interchange

the word "memory" for "address space".

 

No graphics cards, on their own, or with their own BIOS, use any

"system memory". They can't. They don't "own" any. Of course, when

you run X, X will own some system memory that it allocated via mmap(),

and it uses it in conjunction with your AGP card. The internal RAM

within the AGP card is the only RAM in "owns". This is accessible

to the CPU as well as the card electronics. The address range through

which the CPU can access this high-speed RAM is called the Graphics

Aperture and/or the AGP Aperture.

 

This is the same thing as (page 139), "VGA Frame Buffer Size"

for the older PCI/VGA boards.

 

So, if you set your AGP aperture size to overlap address-space where

memory exists, you will probably see streaking and flashing (snow) on

the screen. The bus-contention will also slow your machine during

RAM access and may even cause data corruption in RAM. In other words,

if you have 32 MB of RAM in your screen-card, set the aperture size

to 32 MB, not (!) 256 MB.

 

Cheers,

Dick Johnson

 

Πηγή: http://www.cs.helsinki.fi/linux/linux-kernel/2002-13/0360.html