Serving the Quantitative Finance Community

  • 1
  • 6
  • 7
  • 8
  • 9
  • 10
 
User avatar
Cuchulainn
Posts: 20252
Joined: July 16th, 2004, 7:38 am
Location: 20, 000

sample cuda problems in finance

October 15th, 2015, 4:49 am

QuoteOriginally posted by: AlexEroQuoteOriginally posted by: CuchulainnQuoteIsn't the problem of parallelizing these PDEs tied to the topology of the mesh and the need for each core access values in mesh-adjacent cores? I get the sense that the core-to-core accessibility and bandwidth inside a GPU is particularly poor. Yes. In particular, we can get false sharing when 2 threads modify data stored on the same cache lines.PCI-E bus transfers from/to host<->GPU can kill any algorithmic speedup. The overhead is always 1-5 ms per cudaMemcpy, and cannot be reduced. Hello, Intel.Are you saying that GPUs are insensitive to Amdahl's law? If you have a high serial fraction then no h/w will speed up the algorithm, which is inherently sequential.
 
User avatar
AlexEro
Posts: 145
Joined: November 25th, 2014, 4:27 pm
Location: Ukraine

sample cuda problems in finance

October 15th, 2015, 10:20 am

QuoteOriginally posted by: CuchulainnQuoteOriginally posted by: AlexEroQuoteOriginally posted by: CuchulainnAre you saying that GPUs are insensitive to Amdahl's law? If you have a high serial fraction then no h/w will speed up the algorithm, which is inherently sequential.Nope. I did not say *that*. I am saying that almost any old algorithm can be re-designed to fit GPU with proper speedup. Even more: any MATH problem can be solved by various methods. Who cares that you are using "an old, outdated, less precise, forgotten" method "from 1970"? - if it gives (surprise!) 100X speedup on GPU? Time to dig into old math books, re-considering of all old algos.
 
User avatar
Polter
Posts: 1
Joined: April 29th, 2008, 4:55 pm

sample cuda problems in finance

October 15th, 2015, 10:44 am

QuotePCI-E bus transfers from/to host<->GPU can kill any algorithmic speedup. Right, hence the "accelerator attach" trend (the move to On-Package to On-Chip to On-core).May have to get (re)acquainted with FPGAs, though:http://www.ece.cmu.edu/~calcm/carl/lib/ ... upta.pdfAt the same time, there are also productivity-oriented (in a relative sense) solutions familiar from the GPGPU world:http://www.xilinx.com/about/xcell-publi ... erestingly, as the above illustrates, it's not limited to just Intel-Altera; Xilinx-Qualcomm ARM partnership is worth observing, too:http://semiaccurate.com/2015/10/14/qual ... x-servers/
Last edited by Polter on October 14th, 2015, 10:00 pm, edited 1 time in total.
 
User avatar
Cuchulainn
Posts: 20252
Joined: July 16th, 2004, 7:38 am
Location: 20, 000

sample cuda problems in finance

October 15th, 2015, 11:18 am

QuoteOriginally posted by: AlexEroQuoteOriginally posted by: CuchulainnQuoteOriginally posted by: AlexEroQuoteOriginally posted by: CuchulainnAre you saying that GPUs are insensitive to Amdahl's law? If you have a high serial fraction then no h/w will speed up the algorithm, which is inherently sequential.Nope. I did not say *that*. I am saying that almost any old algorithm can be re-designed to fit GPU with proper speedup. Even more: any MATH problem can be solved by various methods. Who cares that you are using "an old, outdated, less precise, forgotten" method "from 1970"? - if it gives (surprise!) 100X speedup on GPU? Time to dig into old math books, re-considering of all old algos.Too general to respond to.I can't remember any good algos from the 70's. The golden age was the 60s.
 
User avatar
AlexEro
Posts: 145
Joined: November 25th, 2014, 4:27 pm
Location: Ukraine

sample cuda problems in finance

October 15th, 2015, 11:29 am

QuoteOriginally posted by: CuchulainnQuoteOriginally posted by: AlexEroI can't remember any good algos from the 70's. The golden age was the 60s.I agree with you.Besides, I am not a nephew of Putin. Why are you so agressive with my posts here? Or, maybe you are so agressive all the time?
Last edited by AlexEro on October 14th, 2015, 10:00 pm, edited 1 time in total.
 
User avatar
Cuchulainn
Posts: 20252
Joined: July 16th, 2004, 7:38 am
Location: 20, 000

sample cuda problems in finance

October 15th, 2015, 11:53 am

QuoteOriginally posted by: AlexEroQuoteOriginally posted by: CuchulainnQuoteOriginally posted by: AlexEroI can't remember any good algos from the 70's. The golden age was the 60s.I agree with you.Besides, I am not a nephew of Putin. Why are you so agressive with my posts here? Or, maybe you are so agressive all the time?Vladimir is a very good judoka. I think more world leaders should do martial arts. BTW what's the best 70s' algo? or is that a too aggressive question?
Last edited by Cuchulainn on October 14th, 2015, 10:00 pm, edited 1 time in total.
 
User avatar
AlexEro
Posts: 145
Joined: November 25th, 2014, 4:27 pm
Location: Ukraine

sample cuda problems in finance

October 15th, 2015, 1:05 pm

QuoteOriginally posted by: CuchulainnQuoteOriginally posted by: AlexEroQuoteOriginally posted by: CuchulainnQuoteOriginally posted by: AlexEroI can't remember any good algos from the 70's. The golden age was the 60s.I agree with you.Besides, I am not a nephew of Putin. Why are you so agressive with my posts here? Or, maybe you are so agressive all the time?BTW what's the best 70s' algo? or is that a too aggressive question?Yes. Yes!. THIS IS a very agressive question! In order to show my "ignorance" You pretend that You dont know that modern programming (who needs algorithms without programming?)started from UNIX and C programming. UNIX was the best algorithm of modern times! The C language compiler was the best algo of modern times! Why ? Because without those "algos" there will be no all the others.And you pretend that you dont know that ***ing (self-censorship) OS' system time (still) started here and there ...... from 01-Jan-1970. I am very far from the idea that you really dont know that.
Last edited by AlexEro on October 14th, 2015, 10:00 pm, edited 1 time in total.
 
User avatar
Cuchulainn
Posts: 20252
Joined: July 16th, 2004, 7:38 am
Location: 20, 000

sample cuda problems in finance

October 15th, 2015, 3:49 pm

QuoteUNIX was the best algorithm of modern times! Last time I looked was UNIX an OS, but hey, what the heck!let's call it a draw.
 
User avatar
Polter
Posts: 1
Joined: April 29th, 2008, 4:55 pm

sample cuda problems in finance

October 15th, 2015, 5:10 pm