Article: PhysX87: Software Deficiency
By: Richard Cownie (tich.delete@this.pobox.com), July 19, 2010 12:41 pm
Room: Moderated Discussions
Aaron Spink (aaronspink@notearthlink.net) on 7/19/10 wrote:
---------------------------
>And these applications do just fine on OOOE processors and >generally run better and faster on OOOE processors.
Sure. But it's a trade-off of silicon and power. An
OoOE core is the Swiss Army Knife of computing - it does
many things very well. But it's a bit big and bulky for
any particular use. And some fairly important functions
can be done cheaper or faster or at lower power using
in-order cores (or many in-order cores). So yeah, once
you've built your PC with some in-order cores for the 3D
graphics pipeline and some in-order cores for video
decoding and some in-order cores for encryption/decryption
and maybe network packet checksumming and maybe an in-order
core for RAID ECC, then for sure, what's left as the
workload for the "real" CPU is stuff that's not very
well-suited for in-order execution.
Really, I'm a huge fan of OoOE cpu's, and the stuff I
write (a big EDA app traversing 10s of GB of highly-
interlinked data structures) would just suck on an
in-order cpu. But that doesn't blind me to the fact
that there's an awful lot of in-order cores lurking in
an awful lot of hardware and doing a lot of useful stuff
very efficiently, in terms of both silicon area and power.
The argument that those gizmos aren't "real" cpu's seems
to be little more than quibbling over terminology.
>Here's another way to think about it, why did CELL fail so badly? Its pretty much
>the ideal: in-order, software controlled data store, etc. Shouldn't it be blowing everything else out of the water?
As far as I can see, CELL didn't do anything well: the
lousy DP in the early versions made it almost useless for
HPC, the need to manage the memory hierarchy explicitly made
it almost useless for complex apps written in HLLs,
and the rapid advances in Nvidia and ATI's more
specialized 3D chips made it uncompetitive for 3D graphics.
If you want to do something new, it has to provide a
compelling advantage over the competition in some
decent-sized niche. There are lots of ways to fail ...
---------------------------
>And these applications do just fine on OOOE processors and >generally run better and faster on OOOE processors.
Sure. But it's a trade-off of silicon and power. An
OoOE core is the Swiss Army Knife of computing - it does
many things very well. But it's a bit big and bulky for
any particular use. And some fairly important functions
can be done cheaper or faster or at lower power using
in-order cores (or many in-order cores). So yeah, once
you've built your PC with some in-order cores for the 3D
graphics pipeline and some in-order cores for video
decoding and some in-order cores for encryption/decryption
and maybe network packet checksumming and maybe an in-order
core for RAID ECC, then for sure, what's left as the
workload for the "real" CPU is stuff that's not very
well-suited for in-order execution.
Really, I'm a huge fan of OoOE cpu's, and the stuff I
write (a big EDA app traversing 10s of GB of highly-
interlinked data structures) would just suck on an
in-order cpu. But that doesn't blind me to the fact
that there's an awful lot of in-order cores lurking in
an awful lot of hardware and doing a lot of useful stuff
very efficiently, in terms of both silicon area and power.
The argument that those gizmos aren't "real" cpu's seems
to be little more than quibbling over terminology.
>Here's another way to think about it, why did CELL fail so badly? Its pretty much
>the ideal: in-order, software controlled data store, etc. Shouldn't it be blowing everything else out of the water?
As far as I can see, CELL didn't do anything well: the
lousy DP in the early versions made it almost useless for
HPC, the need to manage the memory hierarchy explicitly made
it almost useless for complex apps written in HLLs,
and the rapid advances in Nvidia and ATI's more
specialized 3D chips made it uncompetitive for 3D graphics.
If you want to do something new, it has to provide a
compelling advantage over the competition in some
decent-sized niche. There are lots of ways to fail ...
Topic | Posted By | Date |
---|---|---|
A bit off base | John Mann | 2010/07/07 07:04 AM |
A bit off base | David Kanter | 2010/07/07 11:28 AM |
SSE vs x87 | Joel Hruska | 2010/07/07 12:53 PM |
SSE vs x87 | Michael S | 2010/07/07 01:07 PM |
SSE vs x87 | hobold | 2010/07/08 05:12 AM |
SSE vs x87 | David Kanter | 2010/07/07 02:55 PM |
SSE vs x87 | Andi Kleen | 2010/07/08 02:43 AM |
80 bit FP | Ricardo B | 2010/07/08 07:35 AM |
80 bit FP | David Kanter | 2010/07/08 11:14 AM |
80 bit FP | Kevin G | 2010/07/08 02:12 PM |
80 bit FP | Ian Ollmann | 2010/07/19 12:49 AM |
80 bit FP | David Kanter | 2010/07/19 11:33 AM |
80 bit FP | Anil Maliyekkel | 2010/07/19 04:49 PM |
80 bit FP | rwessel | 2010/07/19 05:41 PM |
80 bit FP | Matt Waldhauer | 2010/07/21 11:11 AM |
80 bit FP | Emil Briggs | 2010/07/22 09:06 AM |
A bit off base | John Mann | 2010/07/08 11:06 AM |
A bit off base | David Kanter | 2010/07/08 11:27 AM |
A bit off base | Ian Ameline | 2010/07/09 10:10 AM |
A bit off base | Michael S | 2010/07/10 02:13 PM |
A bit off base | Ian Ameline | 2010/07/11 07:51 AM |
A bit off base | David Kanter | 2010/07/07 09:46 PM |
A bit off base | Anon | 2010/07/08 12:47 AM |
A bit off base | anon | 2010/07/08 02:15 AM |
A bit off base | Gabriele Svelto | 2010/07/08 04:11 AM |
Physics engine history | Peter Clare | 2010/07/08 04:49 AM |
Physics engine history | Null Pointer Exception | 2010/07/08 06:07 AM |
Physics engine history | Ralf | 2010/07/08 03:09 PM |
Physics engine history | David Kanter | 2010/07/08 04:16 PM |
Physics engine history | sJ | 2010/07/08 11:36 PM |
Physics engine history | Gabriele Svelto | 2010/07/09 12:59 AM |
Physics engine history | sJ | 2010/07/13 06:35 AM |
Physics engine history | David Kanter | 2010/07/09 09:25 AM |
Physics engine history | sJ | 2010/07/13 06:49 AM |
Physics engine history | fvdbergh | 2010/07/13 07:27 AM |
A bit off base | John Mann | 2010/07/08 11:11 AM |
A bit off base | David Kanter | 2010/07/08 11:31 AM |
150 GFLOP/s measured? | anon | 2010/07/08 07:10 PM |
150 GFLOP/s measured? | David Kanter | 2010/07/08 07:53 PM |
150 GFLOP/s measured? | Aaron Spink | 2010/07/08 09:05 PM |
150 GFLOP/s measured? | anon | 2010/07/08 09:31 PM |
150 GFLOP/s measured? | Aaron Spink | 2010/07/08 10:43 PM |
150 GFLOP/s measured? | David Kanter | 2010/07/08 11:27 PM |
150 GFLOP/s measured? | Ian Ollmann | 2010/07/19 01:14 AM |
150 GFLOP/s measured? | anon | 2010/07/19 06:39 AM |
150 GFLOP/s measured? | hobold | 2010/07/19 07:26 AM |
Philosophy for achieving peak | David Kanter | 2010/07/19 11:49 AM |
150 GFLOP/s measured? | Linus Torvalds | 2010/07/19 07:36 AM |
150 GFLOP/s measured? | Richard Cownie | 2010/07/19 08:42 AM |
150 GFLOP/s measured? | Aaron Spink | 2010/07/19 08:56 AM |
150 GFLOP/s measured? | hobold | 2010/07/19 09:30 AM |
150 GFLOP/s measured? | Groo | 2010/07/19 02:31 PM |
150 GFLOP/s measured? | hobold | 2010/07/19 04:17 PM |
150 GFLOP/s measured? | Groo | 2010/07/19 06:18 PM |
150 GFLOP/s measured? | Anon | 2010/07/19 06:18 PM |
150 GFLOP/s measured? | Mark Roulo | 2010/07/19 11:47 AM |
150 GFLOP/s measured? | slacker | 2010/07/19 12:55 PM |
150 GFLOP/s measured? | Mark Roulo | 2010/07/19 01:00 PM |
150 GFLOP/s measured? | anonymous42 | 2010/07/25 12:31 PM |
150 GFLOP/s measured? | Richard Cownie | 2010/07/19 12:41 PM |
150 GFLOP/s measured? | Linus Torvalds | 2010/07/19 02:57 PM |
150 GFLOP/s measured? | Richard Cownie | 2010/07/19 04:10 PM |
150 GFLOP/s measured? | Richard Cownie | 2010/07/19 04:10 PM |
150 GFLOP/s measured? | hobold | 2010/07/19 04:25 PM |
150 GFLOP/s measured? | Linus Torvalds | 2010/07/19 04:31 PM |
150 GFLOP/s measured? | Richard Cownie | 2010/07/20 06:04 AM |
150 GFLOP/s measured? | jrl | 2010/07/20 01:18 AM |
150 GFLOP/s measured? | anonymous42 | 2010/07/25 12:00 PM |
150 GFLOP/s measured? | David Kanter | 2010/07/25 12:52 PM |
150 GFLOP/s measured? | Anon | 2010/07/19 06:15 PM |
150 GFLOP/s measured? | Linus Torvalds | 2010/07/19 07:27 PM |
150 GFLOP/s measured? | Anon | 2010/07/19 09:54 PM |
150 GFLOP/s measured? | anon | 2010/07/19 11:45 PM |
150 GFLOP/s measured? | hobold | 2010/07/19 09:14 AM |
150 GFLOP/s measured? | Linus Torvalds | 2010/07/19 11:56 AM |
150 GFLOP/s measured? | a reader | 2010/07/21 08:16 PM |
150 GFLOP/s measured? | Linus Torvalds | 2010/07/21 09:05 PM |
150 GFLOP/s measured? | anon | 2010/07/22 02:09 AM |
150 GFLOP/s measured? | a reader | 2010/07/22 07:53 PM |
150 GFLOP/s measured? | gallier2 | 2010/07/23 05:58 AM |
150 GFLOP/s measured? | a reader | 2010/07/25 08:35 AM |
150 GFLOP/s measured? | David Kanter | 2010/07/25 11:49 AM |
150 GFLOP/s measured? | a reader | 2010/07/26 07:03 PM |
150 GFLOP/s measured? | Michael S | 2010/07/28 01:38 AM |
150 GFLOP/s measured? | Gabriele Svelto | 2010/07/28 01:44 AM |
150 GFLOP/s measured? | anon | 2010/07/23 04:55 PM |
150 GFLOP/s measured? | slacker | 2010/07/24 12:48 AM |
150 GFLOP/s measured? | anon | 2010/07/24 02:36 AM |
150 GFLOP/s measured? | Vincent Diepeveen | 2010/07/27 05:37 PM |
150 GFLOP/s measured? | ? | 2010/07/27 11:42 PM |
150 GFLOP/s measured? | slacker | 2010/07/28 05:55 AM |
Intel's clock rate projections | AM | 2010/07/28 02:03 AM |
nostalgia ain't what it used to be | someone | 2010/07/28 05:38 AM |
Intel's clock rate projections | AM | 2010/07/28 10:12 PM |
Separate the OoO-ness from speculative-ness | ? | 2010/07/20 07:19 AM |
Separate the OoO-ness from speculative-ness | Mark Christiansen | 2010/07/20 02:26 PM |
Separate the OoO-ness from speculative-ness | slacker | 2010/07/20 06:04 PM |
Separate the OoO-ness from speculative-ness | Matt Sayler | 2010/07/20 06:10 PM |
Separate the OoO-ness from speculative-ness | slacker | 2010/07/20 09:37 PM |
Separate the OoO-ness from speculative-ness | ? | 2010/07/20 11:51 PM |
Separate the OoO-ness from speculative-ness | anon | 2010/07/21 02:16 AM |
Separate the OoO-ness from speculative-ness | ? | 2010/07/21 07:05 AM |
Software conventions | Paul A. Clayton | 2010/07/21 08:52 AM |
Software conventions | ? | 2010/07/22 05:43 AM |
Speculation | David Kanter | 2010/07/21 10:32 AM |
Pipelining affects the ISA | ? | 2010/07/22 10:58 PM |
Pipelining affects the ISA | ? | 2010/07/22 11:14 PM |
Pipelining affects the ISA | rwessel | 2010/07/23 12:03 AM |
Pipelining affects the ISA | ? | 2010/07/23 05:50 AM |
Pipelining affects the ISA | ? | 2010/07/23 06:10 AM |
Pipelining affects the ISA | Thiago Kurovski | 2010/07/23 02:59 PM |
Pipelining affects the ISA | anon | 2010/07/24 07:35 AM |
Pipelining affects the ISA | Thiago Kurovski | 2010/07/24 11:12 AM |
Pipelining affects the ISA | Gabriele Svelto | 2010/07/26 02:50 AM |
Pipelining affects the ISA | IlleglWpns | 2010/07/26 05:14 AM |
Pipelining affects the ISA | Michael S | 2010/07/26 03:33 PM |
Separate the OoO-ness from speculative-ness | anon | 2010/07/21 05:53 PM |
Separate the OoO-ness from speculative-ness | ? | 2010/07/22 04:15 AM |
Separate the OoO-ness from speculative-ness | anon | 2010/07/22 04:27 AM |
Separate the OoO-ness from speculative-ness | slacker | 2010/07/21 07:45 PM |
Separate the OoO-ness from speculative-ness | anon | 2010/07/22 01:57 AM |
Separate the OoO-ness from speculative-ness | ? | 2010/07/22 05:26 AM |
Separate the OoO-ness from speculative-ness | Dan Downs | 2010/07/22 08:14 AM |
Confusing and not very useful definition | David Kanter | 2010/07/22 12:41 PM |
Confusing and not very useful definition | ? | 2010/07/22 10:58 PM |
Confusing and not very useful definition | Ungo | 2010/07/24 12:06 PM |
Confusing and not very useful definition | ? | 2010/07/25 10:23 PM |
Separate the OoO-ness from speculative-ness | someone | 2010/07/20 08:02 PM |
Separate the OoO-ness from speculative-ness | Thiago Kurovski | 2010/07/21 04:13 PM |
You are just quoting SINGLE precision flops? OMG what planet do you live? | Vincent Diepeveen | 2010/07/19 10:26 AM |
The prior poster was talking about SP (NT) | David Kanter | 2010/07/19 11:34 AM |
All FFT's need double precision | Vincent Diepeveen | 2010/07/19 02:02 PM |
All FFT's need double precision | David Kanter | 2010/07/19 02:09 PM |
All FFT's need double precision | Vincent Diepeveen | 2010/07/19 04:06 PM |
All FFT's need double precision - not | Michael S | 2010/07/20 01:16 AM |
All FFT's need double precision - not | Ungo | 2010/07/21 12:04 AM |
All FFT's need double precision - not | Michael S | 2010/07/21 02:35 PM |
All FFT's need double precision - not | EduardoS | 2010/07/21 02:52 PM |
All FFT's need double precision - not | Anon | 2010/07/21 05:23 PM |
All FFT's need double precision - not | Ricardo B | 2010/07/26 07:46 AM |
I'm on a boat! | anon | 2010/07/22 11:42 AM |
All FFT's need double precision - not | Vincent Diepeveen | 2010/07/24 11:39 PM |
All FFT's need double precision - not | slacker | 2010/07/25 03:27 AM |
All FFT's need double precision - not | Ricardo B | 2010/07/26 07:40 AM |
All FFT's need double precision - not | EduardoS | 2010/07/25 08:37 AM |
All FFT's need double precision - not | Michael S | 2010/07/25 10:43 AM |
All FFT's need double precision - not | Vincent Diepeveen | 2010/07/24 11:19 PM |
A bit off base | EduardoS | 2010/07/08 04:08 PM |
A bit off base | Groo | 2010/07/08 06:11 PM |
A bit off base | john mann | 2010/07/08 06:58 PM |
All right...let's cool it... | David Kanter | 2010/07/08 07:54 PM |
A bit off base | Vincent Diepeveen | 2010/07/19 03:36 PM |