Intel(r) core(tm) i7-2600cpu @3.400ghz Has advanced vector extensins Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10
From: [email protected]<mailto:[email protected]> Sent: Friday, 11 June 2021 4:45 PM To: [email protected]<mailto:[email protected]> Subject: wsjt-devel Digest, Vol 88, Issue 35 Send wsjt-devel mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit https://lists.sourceforge.net/lists/listinfo/wsjt-devel or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of wsjt-devel digest..." Today's Topics: 1. Re: Call for information about PC systems being used for WSJT-X (Bill Somerville) 2. Re: Call for information about PC systems being used for WSJT-X (Gary McDuffie) 3. Re: Call for information about PC systems being used for WSJT-X (Reino Talarmo) 4. Re: Call for information about PC systems being used for WSJT-X (Jim Brown) 5. Re: Call for information about PC systems being used for WSJT-X (Jim Brown) 6. Re: Call for information about PC systems being used for WSJT-X (Alan) ---------------------------------------------------------------------- Message: 1 Date: Fri, 11 Jun 2021 01:59:25 +0100 From: Bill Somerville <[email protected]> To: [email protected] Subject: Re: [wsjt-devel] Call for information about PC systems being used for WSJT-X Message-ID: <[email protected]> Content-Type: text/plain; charset=utf-8; format=flowed On 09/06/2021 00:38, Bill Somerville wrote: > Hi all WSJT-X users, > > we are looking into some performance enhancements that will take > advantage of some parallel processing features of modern CPU > architectures. In order to gauge how much backwards compatibility for > older CPUs we will have to implement it would help to know who is > using such older processors. Please don't turn this thread in to a > mine is better than yours conversation, all I need to know is who or > how many of you are using the older CPU architectures. Note that this > applies to MS Windows, Intel Linux, and Intel macOS users, it is about > CPUs not operating systems. > > The technology we will use is called AVX and that is present on all > Intel CPUs branded Core i3/i5/i7/i9 (circa 2010 to present), it is > also present on AMD CPUs since the Jaguar or Puma based CPU models > (some late Athlon-II CPUs, all Zen based CPUs, including Ryzen) circa > 2013 to present. > > Notably Intel CPUs branded Celeron, Pentium, or Atom do not support > the AVX technology. > > So in summary, look up your CPU and if it **does not support AVX** > (https://en.wikipedia.org/wiki/Advanced_Vector_Extensions) then let me > know. > > 73 > Bill > G4WJS. Hi all, thanks for all those who took the time to check their systems and report those without AVX support. That has helped to get a broad picture of the numbers with older CPUs that pre-date this feature. Not unsurprisingly a significant proportion lack AVX, this is almost certainly due to systems being acquired second-hand, repurposed from other uses, or kept for extended periods as they are more than adequate for the average shack PC.? Some have suggested that we should not abandon owners of these older PCs, don't worry as that has never been the intention of this exercise, here is some background that should help to clarify what may happen. The MAP65 application, as of WSJT-X v2.5.0 RC1 has been updated to decode Q65 signals, this is because we feel certain that Q65 is superior for EME use on all bands and the prior JT65 decoding ability will be superseded by Q65. The MAP65 decoder is able to decode many signals across a wide pass-band, and also implements polarization diversity with suitably equipped stations. Automatic linear drift compensation has also been added to compensate for less well specified stations. This all requires a lot of signal processing effort, but users expect signals to be decoded in the short interval between the end of transmission and the start of the next period (note with EME the path delay means that up to 2 1/2 seconds of that interval is lost compared with terrestrial paths). The first use of hand coded micro-optimizations using AVX instructions on suitable CPUs will be aimed at getting Q65 decodes done faster in MAP65. Because the Q65 decoder is shared by WSJT-X and MAP65, the same optimizations will be there for WSJT-X Q65 users. None of this is particularly relevant to the survey of CPUs done here as I am sure that PC costs are such a small part of the typical EME station investment that users will find a way to upgrade their PCs if necessary. So why did I ask the question about AVX? Once we start using AVX for some parts of WSJT-X it makes sense to find other opportunities for similar hand coded micro-optimizations elsewhere in out code base, not only that but once implemented we may well choose to increase the decoding depth of other decoders by taking advantage of such performance gains. The net effect would be that those with AVX equipped PCs will see faster and deeper decoding, those with older PCs will see the same extra depth but overall decoding will take longer than before. My aim was to judge what proportion of users might suffer this speed degradation versus those that will see both faster and deeper decoding. To reassure those that may have misunderstood, there is no intention to exclude users from the latest WSJT-X enhancements just because they have older CPUs. We would implement AVX implementations of critical algorithms alongside their current linear implementations and the choice of which to use would be made at runtime according to the available CPU features. Note exactly this already happens in the FFT library we use called FFTW3, so WSJT-X and MAP65 users have always had AVX specific algorithm implementations for FFT calculations if the CPU they run on supports them. We are investigating coding other critical algorithms in a similar fashion. Notwithstanding that, we also have no intention of dropping support for ARM CPU architectures like the Raspberry Pi, yet we have no intention of similar hand coded micro-optimizations for that platform since the required tools do not exist, so for that platform our linear implementations would still be used, just like on non-AVX Intel or AMD CPUs. 73 Bill G4WJS. ------------------------------ Message: 2 Date: Thu, 10 Jun 2021 20:00:54 -0600 From: Gary McDuffie <[email protected]> To: WSJT software development <[email protected]> Subject: Re: [wsjt-devel] Call for information about PC systems being used for WSJT-X Message-ID: <[email protected]> Content-Type: text/plain; charset=utf-8 Bill, I looked into what I?m running here and found it is a Gen 1 i7 2.67GHz from Intel. Basically says no features on the Intel site, and no mention of AVX or similar on that processor. Gary - AG0N ------------------------------ Message: 3 Date: Fri, 11 Jun 2021 08:07:13 +0300 From: "Reino Talarmo" <[email protected]> To: "'WSJT software development'" <[email protected]> Subject: Re: [wsjt-devel] Call for information about PC systems being used for WSJT-X Message-ID: <[email protected]> Content-Type: text/plain; charset="utf-8" >I looked into what I?m running here and found it is a Gen 1 i7 2.67GHz from >Intel. Basically says no features on the Intel site, and no mention of AVX or >similar on that processor. Hi Gary, You need to dig out the number after "i7-". That tells the actual capabilities of the CPU. I got a feeling that the numbers below 1000 means no AVX support, but higher numbers may also not support. So you need to check it on Intel web page. 73, Reino OH3mA ------------------------------ Message: 4 Date: Thu, 10 Jun 2021 22:10:51 -0700 From: Jim Brown <[email protected]> To: [email protected] Subject: Re: [wsjt-devel] Call for information about PC systems being used for WSJT-X Message-ID: <[email protected]> Content-Type: text/plain; charset=utf-8; format=flowed On 6/9/2021 11:25 AM, Michael Pittaro wrote: > Intel provides tools to do the feature identification for you.? See: > https://www.intel.com/content/www/us/en/support/articles/000005607/boards-and-kits/desktop-boards.html The second choice in this link told me that all my active Thinkpads, the oldest being about 2012-23 vintage, have AVX capability. It took about two minutes per machine to download and run it. 73, Jim K9YC ------------------------------ Message: 5 Date: Thu, 10 Jun 2021 23:09:35 -0700 From: Jim Brown <[email protected]> To: [email protected] Subject: Re: [wsjt-devel] Call for information about PC systems being used for WSJT-X Message-ID: <[email protected]> Content-Type: text/plain; charset=utf-8; format=flowed On 6/10/2021 10:10 PM, Jim Brown wrote: > the oldest being about 2012-23 vintage, Bad fingers -- 2012-2013. Jim ------------------------------ Message: 6 Date: Fri, 11 Jun 2021 07:45:06 +0100 From: Alan <[email protected]> To: WSJT software development <[email protected]>, Bill Somerville <[email protected]> Subject: Re: [wsjt-devel] Call for information about PC systems being used for WSJT-X Message-ID: <179f9d12d50.27fe.308160ffa91046202f89ff6226309...@alangroups.plus.com> Content-Type: text/plain; charset="us-ascii"; Format="flowed" Thanks for the explanation, looks good to me! Alan G0TLK, sent from my mobile device On 11 June 2021 02:01:42 Bill Somerville <[email protected]> wrote: > On 09/06/2021 00:38, Bill Somerville wrote: >> Hi all WSJT-X users, >> >> we are looking into some performance enhancements that will take >> advantage of some parallel processing features of modern CPU >> architectures. In order to gauge how much backwards compatibility for >> older CPUs we will have to implement it would help to know who is >> using such older processors. Please don't turn this thread in to a >> mine is better than yours conversation, all I need to know is who or >> how many of you are using the older CPU architectures. Note that this >> applies to MS Windows, Intel Linux, and Intel macOS users, it is about >> CPUs not operating systems. >> >> The technology we will use is called AVX and that is present on all >> Intel CPUs branded Core i3/i5/i7/i9 (circa 2010 to present), it is >> also present on AMD CPUs since the Jaguar or Puma based CPU models >> (some late Athlon-II CPUs, all Zen based CPUs, including Ryzen) circa >> 2013 to present. >> >> Notably Intel CPUs branded Celeron, Pentium, or Atom do not support >> the AVX technology. >> >> So in summary, look up your CPU and if it **does not support AVX** >> (https://en.wikipedia.org/wiki/Advanced_Vector_Extensions) then let me >> know. >> >> 73 >> Bill >> G4WJS. > > Hi all, > > thanks for all those who took the time to check their systems and report > those without AVX support. That has helped to get a broad picture of the > numbers with older CPUs that pre-date this feature. Not unsurprisingly a > significant proportion lack AVX, this is almost certainly due to systems > being acquired second-hand, repurposed from other uses, or kept for > extended periods as they are more than adequate for the average shack > PC. Some have suggested that we should not abandon owners of these > older PCs, don't worry as that has never been the intention of this > exercise, here is some background that should help to clarify what may > happen. > > The MAP65 application, as of WSJT-X v2.5.0 RC1 has been updated to > decode Q65 signals, this is because we feel certain that Q65 is superior > for EME use on all bands and the prior JT65 decoding ability will be > superseded by Q65. The MAP65 decoder is able to decode many signals > across a wide pass-band, and also implements polarization diversity with > suitably equipped stations. Automatic linear drift compensation has also > been added to compensate for less well specified stations. This all > requires a lot of signal processing effort, but users expect signals to > be decoded in the short interval between the end of transmission and the > start of the next period (note with EME the path delay means that up to > 2 1/2 seconds of that interval is lost compared with terrestrial paths). > The first use of hand coded micro-optimizations using AVX instructions > on suitable CPUs will be aimed at getting Q65 decodes done faster in > MAP65. Because the Q65 decoder is shared by WSJT-X and MAP65, the same > optimizations will be there for WSJT-X Q65 users. None of this is > particularly relevant to the survey of CPUs done here as I am sure that > PC costs are such a small part of the typical EME station investment > that users will find a way to upgrade their PCs if necessary. > > So why did I ask the question about AVX? Once we start using AVX for > some parts of WSJT-X it makes sense to find other opportunities for > similar hand coded micro-optimizations elsewhere in out code base, not > only that but once implemented we may well choose to increase the > decoding depth of other decoders by taking advantage of such performance > gains. The net effect would be that those with AVX equipped PCs will see > faster and deeper decoding, those with older PCs will see the same extra > depth but overall decoding will take longer than before. My aim was to > judge what proportion of users might suffer this speed degradation > versus those that will see both faster and deeper decoding. > > To reassure those that may have misunderstood, there is no intention to > exclude users from the latest WSJT-X enhancements just because they have > older CPUs. We would implement AVX implementations of critical > algorithms alongside their current linear implementations and the choice > of which to use would be made at runtime according to the available CPU > features. Note exactly this already happens in the FFT library we use > called FFTW3, so WSJT-X and MAP65 users have always had AVX specific > algorithm implementations for FFT calculations if the CPU they run on > supports them. We are investigating coding other critical algorithms in > a similar fashion. Notwithstanding that, we also have no intention of > dropping support for ARM CPU architectures like the Raspberry Pi, yet we > have no intention of similar hand coded micro-optimizations for that > platform since the required tools do not exist, so for that platform our > linear implementations would still be used, just like on non-AVX Intel > or AMD CPUs. > > 73 > Bill > G4WJS. > > > > _______________________________________________ > wsjt-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/wsjt-devel -------------- next part -------------- An HTML attachment was scrubbed... ------------------------------ ------------------------------ Subject: Digest Footer _______________________________________________ wsjt-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/wsjt-devel ------------------------------ End of wsjt-devel Digest, Vol 88, Issue 35 ******************************************
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