I am thinking about buying a replacement Apple computer and when started looking at the build options, I found something I didn't know on the Graphic Processors. Apple allows you to chose from three chip sets with the bottom grade included in the price. The middle grade cost an additional $400 and the high end chip runs you $1000. I don't use much in the way of intensive graphics so these chips would be used mostly by SETI. The high end chip set may be more than I want to spend unless somebody can give me a good reason why I should. The main difference I see between the D300 and the D500 is the D500 is much faster on double precision math. I enclosed the information from the Apple web site below if you have questions.

The question is does SETI rely on the double precision math? If not I can save $400 and give a bit more to keep SETI distributing data. If SETI uses double precision math, it looks like the D500 is in my future.

I am not in a rush for an answer so take your time.

Graphics
Mac Pro comes standard with two workstation-class AMD FirePro graphics cards with up to 6GB of GDDR5 VRAM each, enabling powerful GPU-based visualization and compute capabilities in every system. Both GPUs are connected internally via x16 PCI Express gen 3 lanes for massive bandwidth. The FirePro GPUs in Mac Pro enable video output through both the Thunderbolt 2 ports and the HDMI 1.4 port, enabling you to connect up to three 4K displays or up to six Apple Thunderbolt Displays.

Dual AMD FirePro D300 with 2GB GDDR5
Configure your Mac Pro with dual AMD FirePro D300 GPUs for incredibly fast and responsive graphics. Equipped with 2GB of VRAM each on a 256-bit-wide memory bus providing 160GB/s of bandwidth, each FirePro D300 GPU has 1280 stream processors delivering up to 2 teraflops of processing power.

Dual AMD FirePro D500 with 3GB GDDR5
Configure your Mac Pro with dual AMD FirePro D500 GPUs for additional graphics memory bandwidth and processing power. Equipped with 3GB of VRAM each on a 384-bit-wide memory bus providing 240GB/s of bandwidth, each FirePro D500 GPU has 1526 stream processors delivering up to 2.2 teraflops of processing power each. The FirePro D500 supports fast double-precision computations, executing at one-quarter the performance of single-precision floating point rather than the 1/16 performance seen in the D300 and most consumer GPUs.

Dual AMD FirePro D700 with 6GB GDDR5
Tackle the most demanding 3D, 4K video, and scientific visualization problems by configuring your Mac Pro with dual AMD FirePro D700 graphics cards. Equipped with 6GB of VRAM each on a 384-bit-wide memory bus providing 264GB/s of bandwidth, each FirePro D700 GPU has 2048 stream processors delivering up to 3.5 teraflops of processing power each, for a total of 7 teraflops. The FirePro D700 supports fast double-precision computations, executing at one-quarter the performance of single-precision floating point rather than the 1/16 performance seen in the D300 and most consumer GPUs.

Note: AMD FirePro GPUs in Mac Pro support a maximum of two passive DVI adapters such as the Apple Mini DisplayPort to DVI Adapter. Active adapters such as the Apple Mini DisplayPort to Dual-Link DVI Adapter can be used to support more than two DVI displays.

---

Currently the math we do here is only single precision.
There are some MAC people around that are better qualified to answer specif questions, but you may find this link useful.
http://architosh.com/2013/10/the-mac-pro-so-whats-a-d300-d500-and-d700-anyway-we-have-answers/

I found that when I was trying to figure out what GPU they were actually using.

---

SETI@home classic workunits: 93,865 CPU time: 863,447 hours
Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[

Seti only uses single precission.

---

With each crime and every kindness we birth our future.

Thanks for the responses. The link was interesting because I hadn't realized the graphic processors were so expensive. The thought of $3000 for smaller system sounded like an a lot but the system cost only $2000 and the graphic processor is adding from $1000 to $2000 depending on the build option. That doesn't hurt quite so bad in the pocket book!

---

The link was interesting because I hadn't realized the graphic processors were so expensive.

The FirePro series are AMDs professional series cards, used in work station systems. NVidia's are their Quadro series.
Generally work station card prices start where the high end gaming cards end.
Around $1,500 for the base models, I think the top of the pile cards are around $8,000 (cheaper elsewhere- here in Australia we pay more for everything than people do in the US & Europe).

---

Grant
Darwin NT