256MB vs 512MB Graphics Card

[rickwingender]

We are in the process of jumping to Civil 3D 2009 and need some input about the graphics card.

Besides the obvious advantage of the faster card, can someone justify the additional cost of going with a 512 card if a 256 card will do the job, and in fact, will a 256 card actually work good enough to even be considered??

I would like to point out that this card will be in a Dell T3400 workstation with a Core 2 Quad, 4GB RAM and 256MB nVidia Quadro FX570, WinXP Pro

Thanks for the help and advice..........

[cadtag]

well, it's probabaly useful to know that 7 of the 8 processors in the Quad core 2 will be idle when doing anything in AutoCAD or Civil3D unless you plan on rendering, and that 25% of your RAM will be ignored by the OS and application software (actually 50% unless you enable the 3Gig boot switch).

That said, I do see an improvement running the 512 cards vs the 256 mb graphics card in C3D 2008. given the fluffy bling in 2k9, I would expect that the difference there is noticably higher since the 512 mb graphics should handle the overlays and transparency effects better.

[Harold Pei Jr]

well, it's probabaly useful to know that 7 of the 8 processors in the Quad core 2 will be idle when doing anything in AutoCAD or Civil3D unless you plan on rendering, and that 25% of your RAM will be ignored by the OS and application software (actually 50% unless you enable the 3Gig boot switch).

That said, I do see an improvement running the 512 cards vs the 256 mb graphics card in C3D 2008. given the fluffy bling in 2k9, I would expect that the difference there is noticably higher since the 512 mb graphics should handle the overlays and transparency effects better.

He only has a single Quad in that computer, so it should be 3 of the 4.
And it will only see 3 GB to start with, to see the other half gig, he needs to enable the PAE switch. The 3 GB switch deals with allocating the memory, not enabling it.
As for the OP, I'd say that you should get the cheapest card Dell offers, then buy a seperate card. I've noticed some glitches with OpenGL in 2009, nothing major, but irritating. They go away when I switch to the DirectX driver. Unless you install Nvidia's PowerDraft drivers (which are a pain in themselves).