Computer Construction Conundrum
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Nicholas Butler wrote:
What would you do with 48 cores?
Nothing, doubt I'd notice any difference. I rarely use 5% of one core. It's the gfx card that's the limiting factor in games and disk I/O with everything else. Other than a lot of disk thrashing at times in vmware though I don't really have any performance issues. Guess it'd be good for things like folding at home, SETI, etc, but then again the system will probably consume more electricity under load as well.
I agree that outside specialist niches ( science, banking, ... ) there is still no real requirement for today's processors on client machines. But I am seeing real usage on servers with even just tens of concurrent requests. Especially where reads are more common than writes and are serviced from main memory.
Dave Parker wrote:
folding at home
I was expecting Elaine to jump in with that :) Nick
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Have the fastest computer on einstien@home. (unless someone else has a 4way Nehelem running, E@H runs significantly faster on Intel atm).
3x12=36 2x12=24 1x12=12 0x12=18
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*nod* I'm not quite sure what to be looking at there since intel/amd use different numbering schemes for their multi-socket chips than the single socket ones, but for my biggest use intel's cleaning amd's clock. As of late spring this year a ~$1000 s1366 system (to match my existing 1366 for troubleshooting ease) performed roughly on par with 2x$500 amd quad core systems. I know the general performance comparison is less lopsided although I'm not sure what's driving it. E@H is compiled using GCC and at least one of the two apps has hand optimized hot loops written by the guy who ~4 years ago got a 9x speedup vs the stock app by hacking the binary before the project hired him as a consultant to improve their stock apps.
3x12=36 2x12=24 1x12=12 0x12=18
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Nicholas Butler wrote:
Shame that concurrency was dropped from WPF
Only the UI - it's still constrained by the same issues for running STA as hampered WinForms.
Nicholas Butler wrote:
I didn't know that Blend was multi-threaded
Yup.
I have CDO, it's OCD with the letters in the right order; just as they ruddy well should be
Forgive your enemies - it messes with their heads
Pete O'Hanlon wrote:
Only the UI - it's still constrained by the same issues for running STA as hampered WinForms.
This is not such a problem, the reflection is a good work around this restriction.
The narrow specialist in the broad sense of the word is a complete idiot in the narrow sense of the word. Advertise here – minimum three posts per day are guaranteed.
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So, it's time to replace my main dev box. Request for advice &| experience please :) I built my current box for £1200 2.5 years ago. It's a dual quad-core Xeon and I've learnt just about all I can from it. It's been the best £1 per day I've ever spent, but hey! nothing lasts forever... So I've looked around a bit and AMD have released a new range "Magny-Cours" of 8-core and 12-core Opterons at sensible prices. They are basically two quad- or hex-core CPUs in one package for half the price. They have are NUMA ( albeit cache coherent ) as each half of each socket has it's own memory channel. And they all support 2-socket and 4-socket configurations. Very interesting! I'm sorely tempted to build a 48-core box just for fun, but I'm having difficulty convincing myself as my last client still only had up to 8-core boxes. On the other hand, I think that will change soon, and certainly over the next 2.5 years. BTW, I would be using this for writing concurrent business server software. What would you do with 48 cores? Cheers, Nick
Nicholas Butler wrote:
What would you do with 48 cores?
i'd wonder what was going to become of those two bags of apples.
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So, it's time to replace my main dev box. Request for advice &| experience please :) I built my current box for £1200 2.5 years ago. It's a dual quad-core Xeon and I've learnt just about all I can from it. It's been the best £1 per day I've ever spent, but hey! nothing lasts forever... So I've looked around a bit and AMD have released a new range "Magny-Cours" of 8-core and 12-core Opterons at sensible prices. They are basically two quad- or hex-core CPUs in one package for half the price. They have are NUMA ( albeit cache coherent ) as each half of each socket has it's own memory channel. And they all support 2-socket and 4-socket configurations. Very interesting! I'm sorely tempted to build a 48-core box just for fun, but I'm having difficulty convincing myself as my last client still only had up to 8-core boxes. On the other hand, I think that will change soon, and certainly over the next 2.5 years. BTW, I would be using this for writing concurrent business server software. What would you do with 48 cores? Cheers, Nick
I don't understand why you feel the need to build a new machine. Compiler tech certainly is just barely using what you have now. My current quad-core box is 3-4 years old, and I feel no need to upgrade the hardware.
.45 ACP - because shooting twice is just silly
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"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
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"The staggering layers of obscenity in your statement make it a work of art on so many levels." - J. Jystad, 2001 -
*nod* I'm not quite sure what to be looking at there since intel/amd use different numbering schemes for their multi-socket chips than the single socket ones, but for my biggest use intel's cleaning amd's clock. As of late spring this year a ~$1000 s1366 system (to match my existing 1366 for troubleshooting ease) performed roughly on par with 2x$500 amd quad core systems. I know the general performance comparison is less lopsided although I'm not sure what's driving it. E@H is compiled using GCC and at least one of the two apps has hand optimized hot loops written by the guy who ~4 years ago got a 9x speedup vs the stock app by hacking the binary before the project hired him as a consultant to improve their stock apps.
3x12=36 2x12=24 1x12=12 0x12=18
I'm in a niche ( ATM ) market, as I work from home writing concurrent software. The equivalent Intel chips are the 7500 Beckton series. These have 8 cores and 16 threads which according to reports beat the 12-core AMD 6100s. However, I can't find any in stock and the retail prices that are published are prohibitive.
Dan Neely wrote:
the guy who ~4 years ago got a 9x speedup vs the stock app by hacking the binary
Impressive :omg: Nick
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Nicholas Butler wrote:
What would you do with 48 cores?
i'd wonder what was going to become of those two bags of apples.
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I'm in a niche ( ATM ) market, as I work from home writing concurrent software. The equivalent Intel chips are the 7500 Beckton series. These have 8 cores and 16 threads which according to reports beat the 12-core AMD 6100s. However, I can't find any in stock and the retail prices that are published are prohibitive.
Dan Neely wrote:
the guy who ~4 years ago got a 9x speedup vs the stock app by hacking the binary
Impressive :omg: Nick
Nicholas Butler wrote:
Dan Neely wrote: the guy who ~4 years ago got a 9x speedup vs the stock app by hacking the binary Impressive OMG
Yeah. It was really nice for a while since we were getting 9x as many points/day which helped a lot in the bragging rights contest. IIRC he got about ~4-5x from algorithmic changes that were incorporated in the next official app (moving stuff into lookup tables and tweaking working sets to fit inside L1 caches) and ~2x from writing better hot loops to eliminate pipeline stalls and incorporating SSE/SSE2 instructions. The original was pure x87, his replacements interleaved both x87 and SSE instructions to keep both of their pipelines fully loaded. It was eye opening after years of reading that a good compiler is almost impossible to beat these days. Granted that a good C/C++ programmer could have done most of the improvements in his code and used compiler options to get basic SSE1/2 versions, but IIRC we've had 30-50% speedups in new apps after they were regarded as stable enough to start mucking around with asm. Overkill for most uses probably, but at supercomputer work loads even a few percent can help; especially when the total problem set is large enough that probabilistic algorithms are needed to prune the data massively early on. Even with those at present signals need to be an order of magnitude larger than the sensors thresholds to be detected (below that the odds decline roughly linearly), the previous algorithm's sure detection threshold was +2 magnitudes. This is a major challenge when the strongest signal expected from a known pulsar is right at the theoretician detection threshold and is near a massive noise spike.
3x12=36 2x12=24 1x12=12 0x12=18
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I don't understand why you feel the need to build a new machine. Compiler tech certainly is just barely using what you have now. My current quad-core box is 3-4 years old, and I feel no need to upgrade the hardware.
.45 ACP - because shooting twice is just silly
-----
"Why don't you tie a kerosene-soaked rag around your ankles so the ants won't climb up and eat your candy ass..." - Dale Earnhardt, 1997
-----
"The staggering layers of obscenity in your statement make it a work of art on so many levels." - J. Jystad, 2001 -
Nicholas Butler wrote:
Dan Neely wrote: the guy who ~4 years ago got a 9x speedup vs the stock app by hacking the binary Impressive OMG
Yeah. It was really nice for a while since we were getting 9x as many points/day which helped a lot in the bragging rights contest. IIRC he got about ~4-5x from algorithmic changes that were incorporated in the next official app (moving stuff into lookup tables and tweaking working sets to fit inside L1 caches) and ~2x from writing better hot loops to eliminate pipeline stalls and incorporating SSE/SSE2 instructions. The original was pure x87, his replacements interleaved both x87 and SSE instructions to keep both of their pipelines fully loaded. It was eye opening after years of reading that a good compiler is almost impossible to beat these days. Granted that a good C/C++ programmer could have done most of the improvements in his code and used compiler options to get basic SSE1/2 versions, but IIRC we've had 30-50% speedups in new apps after they were regarded as stable enough to start mucking around with asm. Overkill for most uses probably, but at supercomputer work loads even a few percent can help; especially when the total problem set is large enough that probabilistic algorithms are needed to prune the data massively early on. Even with those at present signals need to be an order of magnitude larger than the sensors thresholds to be detected (below that the odds decline roughly linearly), the previous algorithm's sure detection threshold was +2 magnitudes. This is a major challenge when the strongest signal expected from a known pulsar is right at the theoretician detection threshold and is near a massive noise spike.
3x12=36 2x12=24 1x12=12 0x12=18
Dan Neely wrote:
It was eye opening after years of reading that a good compiler is almost impossible to beat these days
yup. i beat it almost every time i try, and i'm a complete ASM novice. and the 'intrinsics' are nearly more trouble than they're worth. i was struggling this weekend to come up with x64 equivalents to some old
_asm {... MMX stuff...}blocks in our code, so i tried the intrinsics. but they ended up being like 4x slower than my hand-written ASM because things were constantly being shoved in and out of the MMX registers instead of being held registers for reuse. -
So, it's time to replace my main dev box. Request for advice &| experience please :) I built my current box for £1200 2.5 years ago. It's a dual quad-core Xeon and I've learnt just about all I can from it. It's been the best £1 per day I've ever spent, but hey! nothing lasts forever... So I've looked around a bit and AMD have released a new range "Magny-Cours" of 8-core and 12-core Opterons at sensible prices. They are basically two quad- or hex-core CPUs in one package for half the price. They have are NUMA ( albeit cache coherent ) as each half of each socket has it's own memory channel. And they all support 2-socket and 4-socket configurations. Very interesting! I'm sorely tempted to build a 48-core box just for fun, but I'm having difficulty convincing myself as my last client still only had up to 8-core boxes. On the other hand, I think that will change soon, and certainly over the next 2.5 years. BTW, I would be using this for writing concurrent business server software. What would you do with 48 cores? Cheers, Nick
Nicholas Butler wrote:
What would you do with 48 cores?
Fully describe the high power DE stray energy problem Recreate my college "Lana" (Lexical Analysis) and add AI Make some killer raytraces.... Increase my RF-LOS work even more.... Massive amounts of soft-body physics.... "wouldn't you love to get your hands on one of those gibsons...." :-D
_________________________ John Andrew Holmes "It is well to remember that the entire universe, with one trifling exception, is composed of others." Shhhhh.... I am not really here. I am a figment of your imagination.... I am still in my cave so this must be an illusion....
modified on Monday, September 20, 2010 3:09 PM
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Nicholas Butler wrote:
What would you do with 48 cores?
i'd wonder what was going to become of those two bags of apples.
Chris Losinger wrote:
i'd wonder what was going to become of those two bags of apples.
Apple cobbler!
_________________________ John Andrew Holmes "It is well to remember that the entire universe, with one trifling exception, is composed of others." Shhhhh.... I am not really here. I am a figment of your imagination.... I am still in my cave so this must be an illusion....
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From comments made elsewhere I don't think is using all zillion cores to compile on, he's writing apps that scale across a zillion cores.
3x12=36 2x12=24 1x12=12 0x12=18
Dan Neely wrote:
he's writing apps that scale across a zillion cores.
The only way to fly!! :-D :-D
_________________________ John Andrew Holmes "It is well to remember that the entire universe, with one trifling exception, is composed of others." Shhhhh.... I am not really here. I am a figment of your imagination.... I am still in my cave so this must be an illusion....
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Chris Losinger wrote:
i'd wonder what was going to become of those two bags of apples.
Apple cobbler!
_________________________ John Andrew Holmes "It is well to remember that the entire universe, with one trifling exception, is composed of others." Shhhhh.... I am not really here. I am a figment of your imagination.... I am still in my cave so this must be an illusion....
pie would be acceptable, also.
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probably a fan of the banana.
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pie would be acceptable, also.
Chris Losinger wrote:
pie would be acceptable, also.
true... but since he is considering cobbling together his own computer... I figured a cobbler was slightly more accurate. :)
_________________________ John Andrew Holmes "It is well to remember that the entire universe, with one trifling exception, is composed of others." Shhhhh.... I am not really here. I am a figment of your imagination.... I am still in my cave so this must be an illusion....
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Chris Losinger wrote:
pie would be acceptable, also.
true... but since he is considering cobbling together his own computer... I figured a cobbler was slightly more accurate. :)
_________________________ John Andrew Holmes "It is well to remember that the entire universe, with one trifling exception, is composed of others." Shhhhh.... I am not really here. I am a figment of your imagination.... I am still in my cave so this must be an illusion....
good point. cobbler it is!
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Nicholas Butler wrote:
What would you do with 48 cores?
Fully describe the high power DE stray energy problem Recreate my college "Lana" (Lexical Analysis) and add AI Make some killer raytraces.... Increase my RF-LOS work even more.... Massive amounts of soft-body physics.... "wouldn't you love to get your hands on one of those gibsons...." :-D
_________________________ John Andrew Holmes "It is well to remember that the entire universe, with one trifling exception, is composed of others." Shhhhh.... I am not really here. I am a figment of your imagination.... I am still in my cave so this must be an illusion....
modified on Monday, September 20, 2010 3:09 PM
El Corazon wrote:
Massive amounts of soft-body physics
your internet connection will have more of an effect on that than sheer processing power.
image processing toolkits | batch image processing
modified on Monday, September 20, 2010 4:31 PM
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El Corazon wrote:
Massive amounts of soft-body physics
your internet connection will have more of an effect on that than sheer processing power.
image processing toolkits | batch image processing
modified on Monday, September 20, 2010 4:31 PM
Chris Losinger wrote:
your internet connection will have more of an effect on that then sheer processing power.
I wonder how many heads that will go over?? :laugh:
_________________________ John Andrew Holmes "It is well to remember that the entire universe, with one trifling exception, is composed of others." Shhhhh.... I am not really here. I am a figment of your imagination.... I am still in my cave so this must be an illusion....