Best video card for mac pro

Question

Mac Pro Info:2x2.66 GHz Dual-Core Intel Xeon
MacPro1, 1
It says my mac pro (2006-2007) model had PCIe slots, but it doesn't mention PCI 2.0 slots.  i'm looking to upgrade my video card to one of the better ones for this computer.  currently i have a radeon x1900 XT 512 card.  it can get clunky at times.  I've been reading a lot about the Radeon HD5770, but it says it works with PCI 2.0.   i've been reading that a lot of people that currently have the x1900 XT upgrade to the HD5770.  but I don't want to buy an incompatible one.  I just did that on my RAM and had to return it.
     Does anyone know if this card will work?  and will both mini display ports work as well?
or do you have a better suggestion for an upgrade? 
i don't do a whole lot of gaming, but i like having a junky desktop with 30 browser windows open and 10 other programs open at the same time.  i would like a card that is good for that.  thanks again!

Answer 1

OpenGL 3.2 support15
Image quality enhancement technology 
Up to 24x multi-sample and super-sample anti-aliasing modes
Adaptive anti-aliasing
16x angle independent anisotropic texture filtering
128-bit floating point HDR rendering
http://www.amd.com/us/products/desktop/graphics/ati-radeon-hd-5000/hd-5770/Pages /ati-radeon-hd-5770-overview.aspx#5
X1900 http://www.amd.com/us/products/desktop/graphics/other/Pages/x1900-specifications .aspx
not all ATI Radeon graphics cards are HDCP ready.
Complete feature set also supported in OpenGL® 2.0
Barefeats: adding the Radeon HD 5870 or 5770 to your 2006 Mac Pro won't cause it to "leap tall buildings in a single bound." But these new cards will help you "clear low buildings with a running start."
OpenGL 2.1  Released on July 2, 2006. Where is the 4.2 support, or even 3.2 support??
Apple lags by over half a decade and has not done much to modernize graphic driver support to current available standards.
OpenGL 4.2  Released on 8 August 2011[33]
Supported Cards: Nvidia GeForce 400 series, Nvidia GeForce 500 series, Nvidia GeForce 600 series, ATI Radeon HD 5000 series, AMD Radeon HD 6000 Series, AMD Radeon HD 7000 Series
Support for shaders with atomic counters and load/store/atomic read-modify-write operations to a single level of a texture.
Capturing GPU-tessellated geometry and drawing multiple instances of the result of a transform feedback to enable complex objects to be efficiently repositioned and replicated.
Support for modifying an arbitrary subset of a compressed texture, without having to re-download the whole texture to the GPU for significant performance improvements.
Support for packing multiple 8 and 16 bit values into a single 32-bit value for efficient shader processing with significantly reduced memory storage and bandwidth.
http://en.wikipedia.org/wiki/OpenGL
OpenCL 1.1 was ratified by the Khronos Group on 14 June 2010 - "Hello, that is full two years ago." http://en.wikipedia.org/wiki/OpenCL#cite_note-11
OpenCL 1.2  On 15 November 2011, the Khronos Group announced the OpenCL 1.2 specification,[13] which added significant functionality over the previous versions in terms of performance and features for parallel programming. Most notable features include:
Device partitioning: the ability to partition a device into sub-devices so that work assignments can be allocated to individual compute units. This is useful for reserving areas of the device to reduce latency for time-critical tasks.
Separate compilation and linking of objects: the functionality to compile OpenCL into external libraries for inclusion into other programs.
Enhanced image support: 1.2 adds support for 1D images and 1D/2D image arrays. Furthermore, the OpenGL sharing extensions now allow for OpenGL 1D textures and 1D/2D texture arrays to be used to create OpenCL images.
http://en.wikipedia.org/wiki/OpenCL
OpenCL is a trademark of Apple Inc.