This may be difficult to read as I cannot seem to get the tab function to work properly, so I apologize in advance. A friend of mine has a son whose hobby appears to be upgrading his graphics card every week or so. He has recently left for college and has left behind a pile of so called "junk". Among the pile are the following cards that have been generously offered to me and also match the the BOINC compatability list (at least as I read it): GeForce 210 512mb DDR2 PCIe 2.0, GeForce 8400 512mb DDR2 PCIe, GeForce 210 512mb DDr3 PCIe, Radeon HD 5450 512mb DDR2 PCIe 2.1, Radeon HD 4650 1Gb DDR2 PCIe 2.0. A few questions come to mind. When it comes to crunching power, which card property is most important? Is a 1Gb DDR2 card superior to a 512mb DDR3 card? PCIe vs. PCIe 2.0 or 2.1? Also, I noticed that the BOINC list had the 210 series cards marked as OEM only. Is this a concern? I did not bother to note the manufacturer. Finally, unless there is a major difference in output, I would prefer to use a CUDA card due to the greater number of supported projects. Thanks in advance...

OEM only means you can't purchase it directly from the card manufacturer, it's part of a system, such as Dell, HP, etc... As far as PCIe vs PCIe 2.0 or 2.1, your motherboard specs are what matters. A 2.1 motherboard SHOULD be compatible with a 2.0 card, but not the other way around (2.1 card may not work in a 2.0 motherboard.) All other matters being equal, go for MFlops/sec.

GeForce 210 512 MB has 589 MHz Graphics Clock, 1402 MHz Processor Clock, 8 GB/sec Memory Bandwidth, 500 MHz Memory Clock, 30.5 watts
GeForce 8400 512 MB has 567 MHz Graphics Clock, 1400 MHz Processor Clock, 6.4 GB/sec Memory Bandwidth, 400 MHz Memory Clock
Radeon HD5450 512 MB has 650 MHz Graphics Clock, 6.4 GB/sec Memory Bandwidth, 400 MHz Memory Clock, 19.1 watts
Radeon HD4650 1 GB has 600 MHz Graphics Clock, 21.3 GB/s Memory Bandwidth, 667MHz Memory Clock

BTW, I'll pay for shipping on any cards you don't want

@ AKTigger: One of the first things I mentioned was having a source to get rid of all of them.

There is a website I would recommend that can help you a lot with your research into these cards.... http://www.gpureview.com

There is a menu item near the top left of the main page "Compare Cards" which is a very helpful tool. Here are my thoughts on the matter ...

Although CUDA cards give you more flexibility with the number of projects to choose from, it seems to me currently that the projects allowing the use of ATI cards give you more credits -- more bang for your buck, if you will. Because you will be using the GPU to crunch and not necessarily for monitor display purposes, the AMOUNT of memory is not a huge factor -- all other things being equal, choose faster memory over quantity of memory.

What makes these GPUs good crunchers is there ability to do massively parallel processing, so basically (most importantly in my opinion) the more processors (often called shaders or similar terms) the better.

If all else fails ... generally the more powerful the card, the more energy it will consume -- so if you're at a loss to choose, choose the one consuming the largest number of watts of energy


Of course, as already mentioned, make sure the card is compatible with your motherboard (this shouldn't be a huge issue -- all cards being PCI-E -- as long as you have a PCI-Ex16 slot on your board you should be OK).

Being a cheapskate (read: short on cash) I'm looking for a reasonable graphics card to upgrade an older PC, and am looking at whether it's worth my while to get a card that has a compatible GPU for crunching purposes.

My idea of "reasonable" being under US$50, I found the MSI nVidia GeForce 8400GS (available for around $32). My question is this: is the chipset in this card likely to significantly improve my crunching, or should I be looking for something a little further up the scale?

I realise that I'm probably going to have to install different drivers and whatnot, but have to confess to being a little clueless on the whole CUDA thing.

Any advice you could offer this cash-strapped cruncher would be gratefully received.

Check MicroCenter.com: Galaxy GeForce 8400GS 256MB DDR2 for US$10.99 after rebate. Also, 512MB version for US$12.99. Not sure about shipping.

Gads, video cards are a lot cheaper than they used to be.

Sorry for the very late reply, but here is how I see your card options:

The 4650 is by far the best card. 320 stream processors. OpenCL capable. (about 2100secs on Collatz work, about 9000secs on PrimeGrid)

The 5450 is next fastest. 80 stream processors (you can increase the Collatz and PG times from the 4650 by a factor of 3x-4x).

The Geforce 210's and 8400GS all have 16 shaders (note that ATI stream processors are different...16 shaders is equivalent to about 40 stream processors). These are all slow, so many of the CUDA projects will not be useful since work will not be able to be completed under deadlines. That said, the 210's are better overall (later version of Direct X, etc.) for general use. DDR3 will have very small performance gains over DDR2 on such cards, and these will be almost nothing in BOINC projects. (Collatz time on my 8400GS is around 30000sec).

Thanks, Scott. At this point, I was given a 9500GT and paid 20 USD for a used 8800GT. Of particular interest was the bit about 16 shaders being roughly equivalent to 40 stream processors. I instinctively knew there must be a difference, otherwise A HD5770 would destroy a GTX470. It is nice to have it quantified. This will help me choose when I upgrade and have to pay retail price. Of course, there's always that jolly old fellow with the sleigh and reindeer. It is rumored he may make an appearance soon....