Hey,
Does anyone have a Pismo Logic board lying around, I'm curious about the ATI Mobility 128 section on the underside of the Logic Board, but I don't yet want to take apart my unit.
The only picture I could find online was this;
http://www.pbfixit.com/Guide/Pismo/images/57 PH_12151/57 PH_fmt.jpeg
Of course, the resolution is to low to really see anything in detail. I assume that the ATI Mobility 128 is hidden underneath that heat sink shown in the image.
If anyone has access to a (dead?) Pismo Logic board, could they try removing the Heatsink on the underside of the logic board and take a digital picture of the ATI graphics chip.
Why do I want this? Well, the Rage Mobility 128 has the potential to use 16mb of VRAM. Apple only shipped Powerbooks with 8mb however. Without the full 16Mb, the memory bus between the GPU & VRAM is reduced to 64-bit. With the full 16mb, the memory bus is upped to 128-bit.
If you check the bechmarks @ http://www.anandtech.com/printarticle.html?i=1198 you can see what a drastic hit the stock 8mb VRAM (64-bit) has on 3d games compared to the 16mb (128-bit) version of the Rage mobility 128, FPS benchmarks are "doubled" or even "tripled" with the latter.
Which makes you wonder, Why would apple have shipped there top of the line Powerbooks (at the time) with only 8mb of VRAM when may PC laptops opted for the full 16mb. It obviously would have given the Powerbooks a huge boost in 3d gaming, especially using 32-bit modes in 3D games. It boggles the mind why they (apple) wouldn't have wanted an easy & cheap way to improve GPU performance, which were at that time their top of the line notebooks.
Off the point, but another thing thats annoying is that Apple's ATI Mobility 128 drivers don't utilize the onboard hardware DVD decoder that was built into ATI's chip, opting instead for software decoding. Offloading the burden of decoding DVD's through a powerbooks CPU and giving it to the GPU's hardware decoder would have significantly improved battery life when watching DVD's when mobile.
Well anyways..... I think that there's a good chance there was space made available on the logic board to accomidate the external 8Mb VRAM support, it was probably just a latter decision not to actually solder the extra VRAM to the logic board (I have 1997 PC laptop that did the same thing)..... so maybe an experienced person could actually find the same VRAM used and solder/install it themselves.
I like my Pismo and don't really have any money or interest in replacing it with another Powerbook for a long whiles, so this is why I'm interested in the modification possibility.
p9
Does anyone have a Pismo Logic board lying around, I'm curious about the ATI Mobility 128 section on the underside of the Logic Board, but I don't yet want to take apart my unit.
The only picture I could find online was this;
http://www.pbfixit.com/Guide/Pismo/images/57 PH_12151/57 PH_fmt.jpeg
Of course, the resolution is to low to really see anything in detail. I assume that the ATI Mobility 128 is hidden underneath that heat sink shown in the image.
If anyone has access to a (dead?) Pismo Logic board, could they try removing the Heatsink on the underside of the logic board and take a digital picture of the ATI graphics chip.
Why do I want this? Well, the Rage Mobility 128 has the potential to use 16mb of VRAM. Apple only shipped Powerbooks with 8mb however. Without the full 16Mb, the memory bus between the GPU & VRAM is reduced to 64-bit. With the full 16mb, the memory bus is upped to 128-bit.
If you check the bechmarks @ http://www.anandtech.com/printarticle.html?i=1198 you can see what a drastic hit the stock 8mb VRAM (64-bit) has on 3d games compared to the 16mb (128-bit) version of the Rage mobility 128, FPS benchmarks are "doubled" or even "tripled" with the latter.
Which makes you wonder, Why would apple have shipped there top of the line Powerbooks (at the time) with only 8mb of VRAM when may PC laptops opted for the full 16mb. It obviously would have given the Powerbooks a huge boost in 3d gaming, especially using 32-bit modes in 3D games. It boggles the mind why they (apple) wouldn't have wanted an easy & cheap way to improve GPU performance, which were at that time their top of the line notebooks.
Off the point, but another thing thats annoying is that Apple's ATI Mobility 128 drivers don't utilize the onboard hardware DVD decoder that was built into ATI's chip, opting instead for software decoding. Offloading the burden of decoding DVD's through a powerbooks CPU and giving it to the GPU's hardware decoder would have significantly improved battery life when watching DVD's when mobile.
Well anyways..... I think that there's a good chance there was space made available on the logic board to accomidate the external 8Mb VRAM support, it was probably just a latter decision not to actually solder the extra VRAM to the logic board (I have 1997 PC laptop that did the same thing)..... so maybe an experienced person could actually find the same VRAM used and solder/install it themselves.
I like my Pismo and don't really have any money or interest in replacing it with another Powerbook for a long whiles, so this is why I'm interested in the modification possibility.
p9