0

This videocard (Radeon HD 4850) conforms only with OpenCL 1.0, per AMD Compatibility table. I need some hardware to conduct intensive financial calculations with doubleN types (no floats at all!). According to this cardtable, this card is able to work with double types. Now I have the possibility to buy it at quite an attractive price.

I'd greatly appreciate if an answerer has real experience in working with this card for OpenCL with fp64 extension. Of course, if there are problems with this card, please put two lines here.

Thank you and sorry for my English.

toughbummer
  • 1
  • 1

2 Answers2

0

I haven't used this card with DP before, but if the spec says it is supported, then it's worth a try.

In my opinion, you should go with a newer model card though. There are a lot of cheap cards out that will outperform the 4850, and they will support some new features as well.

mfa
  • 5,017
  • 2
  • 23
  • 28
  • Thank you, @mfa. Still waiting for somebody who has used it with DP. – toughbummer May 18 '12 at 13:51
  • OK, the issue is closed. I feel it's better to buy something like HD 5870 or HD 6930, these aren't too expensive. – toughbummer May 19 '12 at 23:55
  • That's a good choice. The ones ending with 70 are the good ones. 5770 6770 and 7770 are top performing mid-range cards to check out. 5870 is a great card too. – mfa May 20 '12 at 06:43
0

This card supports double precision but the 4xxx series doesn't include local memory in the chip. As the standard mandates local memory support it is emulated with global memory and very slow. Many algorithms require local memory for obtaining a good speed-up. So, a newer card 5xxx and higher is a lot better.

In addition, some combinations of older cards/older SDK versions only support double precision through the cl_amd_fp64 extension (not the official cl_khr_fp64 extension) because of some small things from the standard that are not supported. For the most part, this doesn't matter much except that you need to change the extension name in your code to make it work with doubles.

As a general tip, I would try to avoid the 4xxx series if you intend to make serious GPGPU development. Keep in mind also, that the newer 7xxx series it is much more optimized for GPU computations than both the 5xxx and 6xxx series closing much of the gap with NVIDIA cards. So, if you can, try to aim for a 7xxx with double precision support.

Josep
  • 36
  • 3