[Chimera-users] Graphics cards for Mac

[Jeff Speir]

Thanks for the valuable info Tom, Greg.

Apple advertised 10.5 Leopard as a 64-bit OS top to bottom.  Is this  
not true for the graphics?  Can any of the graphics programs running  
in Leopard access 64-bit memory space?

Thanks,

Jeff


On Mar 4, 2008, at 10:48 AM, Greg Couch wrote:

> Another take home message is that if you want chimera to run faster
> drawing molecules, get a faster CPU.  This is true for all platforms
> chimera runs on (Mac OS X, Windows, Linux, ...).  For example, both  
> the
> Quadro system and the HD 2600 systems mentioned had 2.8 Ghz CPU's and
> Apple sells 3.0 and 3.2 Ghz systems for $800 and $1600 additional cost
> respectively.  I would expect the improvement to be roughly linear  
> with
> the CPU speed change, so +7% and +14%.  But we'll have to wait for  
> someone
> to do the benchmarks to be sure.
>
> Being CPU limited is not a feature, but to fix it will take a  
> rewrite of
> the chimera internals and we're still evaluating how best to do it.
>
>  	Greg Couch
>  	UCSF Computer Graphics Lab
>
> On Tue, 4 Mar 2008, Tom Goddard wrote:
>
>> Here's a comparison of Chimera graphics benchmarks for the current
>> standard PowerMac graphics versus the top-of-the-line graphics:
>>
>>    Radeon HD 2600 - no additional cost
>>    Quadro FX 5600 - $2850 additional cost
>>
>> Surfaces and meshes: 1.8x faster
>>
>> Volume solid style:  size 443**3 vs 325**3.  Quadro system was  
>> limited
>> 32-bit main memory address space.
>>
>> Molecule: Neglible difference for 34000 atom model in wire, stick,  
>> ball
>> and stick, ribbon, sphere styles.
>>
>> The Quadro card has 1.5 Gbytes of memory and will probably have
>> significantly higher performance on solid style volume rendering  
>> if the
>> Chimera volume display code is optimized.  Probably adding more main
>> memory will not help because the limitation is the 32-bit address  
>> space
>> (a limit of Mac OS graphical applications).
>>
>> The Quadro card did not correctly display volume data in solid style
>> with 3d textures (solid rendering 2d texture option turned off) --
>> displayed a chessboard pattern.  Did not test 3d textures on  
>> Radeon card.
>>
>>    Tom
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