Intel Xeon PHI? - Page 15

paulunderwood · 2021-02-11, 06:05

Quote:

Originally Posted by octonion

Sadly, I can't get my Xeon Phi workstation to display output. Reseated the power connections, checked the jumpers, cleared the CMOS and reset the BIOS, tried three different monitors with VGA input. It may simply be a bad VGA cable, despite it being brand new. I'd hate to have to return it.

Have you tried without the Phi plugged in? It may be that you have to set the video in BIOS.

Please provide a link to the board's manual.

Update: Please disregard my suggestion -- I did not understand the architecture; I thought the Phi was a card. Are any DIMMs you are using bad? Would hooking up the IPMI help diagnose the problem?

octonion · 2021-02-11, 08:27

I don't have any DIMMs installed, I'm just using the 16GB on-package. The fans spin up fast, then gradually slow down, which I believe is the expected behavior. No VGA output on the three monitors I tried, but I only have one VGA cable, a new Monoprice VGA cable I just bought.

LED1 (hard drive activity) is red - note I don't have any drives installed.
LEDM1 (BMC activity) is blinking green - which seems to be normal.

paulunderwood · 2021-02-11, 08:39

And IPMI? If you plug in a LAN cable to the IPMI socket, can you find the server? It needs to aquire an IP address from a DHCP server. Your router will have one and I think Windows has one by default???

ewmayer · 2021-02-12, 00:28

Quote:

Originally Posted by octonion

I don't have any DIMMs installed, I'm just using the 16GB on-package. The fans spin up fast, then gradually slow down, which I believe is the expected behavior. No VGA output on the three monitors I tried, but I only have one VGA cable, a new Monoprice VGA cable I just bought.

LED1 (hard drive activity) is red - note I don't have any drives installed.
LEDM1 (BMC activity) is blinking green - which seems to be normal.

Were you using any of your monitors with a working system, and if so, how did you connect them (it)?

Per the mobo manual, LED2 is the HDD Activity LED, and "Green: (On/Blinking): HDD active". Red sounds bad - perhaps it won'y boot without a drive? I never tried my KNL without the SSD I bought for it. My LED2 is not lit at all, but that may be because the work I'm doing only rarely does disk writes, maybe every 10 minutes.

ewmayer · 2021-02-18, 03:39

I've previously reported fiddling the CPU settings via BIOS to fixed-frequency and single-thread mode, been running stably that way for some months, seemed to have no appreciable effect - plus or minus - on per-iter times of my F30 DC run@64M FFT, or system temps. More recently decided to see what the effect of running a 4-threaded LL-DC assignment on the 'idle' physical cores 64-67 would be - was pleasantly surprised, F30 job slowed down maybe 3%, LL-DC @ 3M FFT was getting ~24 msec/iter, roughly half the speed of that FFT length using just those 4 cores, i.e. w/o memory-bus contention from the big F30 run.

Recently decided to move the system to a different corner of the LR, on the hardwood floor in a little corner nearly-under a window which is at least cracked most of the time for ventilation. (But system is well out of harm's way as rain/wind/flying-debris goes). Before doing so decided to revert the CPU settings, to allow me to once again play with multiple-threads-per-physical core. On reboot and restart of the above 2 jobs at the same #nthreads and core affinities as before, the F30 job was maybe 1-2% faster, but the little 4-thread DC timing dropped to 20 ms/iter. I suspect re-enabling hyerthreading allows the OS to do a better job at balancing system and user tasks. Oh, it's not a temperature effect - system temps are ~5C *higher* in the new location (~60C vs ~55C, since the open case side is now ~1" from the wall, whereas before it was wide open, with the system raised up around 2 feet from the floor on a pedestal.

octonion · 2021-02-26, 01:07

I received my replacement Xeon Phi system, and it works perfectly! It installed Ubuntu 20.04 no problem, and in fact I'm sending this message on it while listening to some music over my Logitech G930 wireless headphones. My wireless Logitech MX Master mouse also works fine, as does my USB WiFi dongle. I received a system with a 7250 Xeon Phi CPU, so it actually has 68 cores and 272 threads.

It does 1080p (1920x1080) via the VGA/SVGA port, and the display quality is excellent.

paulunderwood · 2021-02-26, 13:13

There are a number of 56/60 22nm Xeon Phi on ebay.co.uk at the moment for about £100. What are the adavantages? -- 60 GHz is lot; Do the have AVX2?. Apart from being 250w what are the disadvantages? -- cooling?; This would be okay during the winter.

Looking through this thread they seem to be tomorrow's silicon rubbish. The 7210 is the way to go, having AVX512

octonion · 2021-02-28, 00:39

Compiled OpenBLAS for up to 256 threads. Works fine!

paulunderwood · 2021-02-28, 08:23

Quote:

Originally Posted by octonion

Compiled OpenBLAS for up to 256 threads. Works fine!

Can you run mprime on it out of the box or do you have to compile it to get it working on your Phi?

octonion · 2021-03-05, 04:09

Quote:

Originally Posted by paulunderwood

Can you run mprime on it out of the box or do you have to compile it to get it working on your Phi?

mprime recognizes the Xeon Phi supports AVX-512 out of the box.

ewmayer · 2021-03-05, 20:15

Quote:

Originally Posted by octonion

mprime recognizes the Xeon Phi supports AVX-512 out of the box.

What worker/thread combination does its auto-tuner suggest is best in total-throughput terms?

2021-02-11, 08:39	#157
paulunderwood Sep 2002 Database er0rr 7041₈ Posts	And IPMI? If you plug in a LAN cable to the IPMI socket, can you find the server? It needs to aquire an IP address from a DHCP server. Your router will have one and I think Windows has one by default??? Last fiddled with by paulunderwood on 2021-02-11 at 08:57

2021-02-26, 13:13	#161
paulunderwood Sep 2002 Database er0rr 3617₁₀ Posts	There are a number of 56/60 22nm Xeon Phi on ebay.co.uk at the moment for about £100. What are the adavantages? -- 60 GHz is lot; Do the have AVX2?. Apart from being 250w what are the disadvantages? -- cooling?; This would be okay during the winter. Looking through this thread they seem to be tomorrow's silicon rubbish. The 7210 is the way to go, having AVX512 Last fiddled with by paulunderwood on 2021-02-26 at 13:41

2021-02-28, 00:39	#162
octonion Feb 2021 111₂ Posts	OpenBLAS Compiled OpenBLAS for up to 256 threads. Works fine! Attached Thumbnails

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2021-02-11, 08:27	#156
octonion Feb 2021 7 Posts	I don't have any DIMMs installed, I'm just using the 16GB on-package. The fans spin up fast, then gradually slow down, which I believe is the expected behavior. No VGA output on the three monitors I tried, but I only have one VGA cable, a new Monoprice VGA cable I just bought. LED1 (hard drive activity) is red - note I don't have any drives installed. LEDM1 (BMC activity) is blinking green - which seems to be normal.

2021-02-18, 03:39	#159
ewmayer ∂²ω=0 Sep 2002 República de California 3·5³·31 Posts	I've previously reported fiddling the CPU settings via BIOS to fixed-frequency and single-thread mode, been running stably that way for some months, seemed to have no appreciable effect - plus or minus - on per-iter times of my F30 DC run@64M FFT, or system temps. More recently decided to see what the effect of running a 4-threaded LL-DC assignment on the 'idle' physical cores 64-67 would be - was pleasantly surprised, F30 job slowed down maybe 3%, LL-DC @ 3M FFT was getting ~24 msec/iter, roughly half the speed of that FFT length using just those 4 cores, i.e. w/o memory-bus contention from the big F30 run. Recently decided to move the system to a different corner of the LR, on the hardwood floor in a little corner nearly-under a window which is at least cracked most of the time for ventilation. (But system is well out of harm's way as rain/wind/flying-debris goes). Before doing so decided to revert the CPU settings, to allow me to once again play with multiple-threads-per-physical core. On reboot and restart of the above 2 jobs at the same #nthreads and core affinities as before, the F30 job was maybe 1-2% faster, but the little 4-thread DC timing dropped to 20 ms/iter. I suspect re-enabling hyerthreading allows the OS to do a better job at balancing system and user tasks. Oh, it's not a temperature effect - system temps are ~5C higher in the new location (~60C vs ~55C, since the open case side is now ~1" from the wall, whereas before it was wide open, with the system raised up around 2 feet from the floor on a pedestal.

2021-02-26, 01:07	#160
octonion Feb 2021 7 Posts	I received my replacement Xeon Phi system, and it works perfectly! It installed Ubuntu 20.04 no problem, and in fact I'm sending this message on it while listening to some music over my Logitech G930 wireless headphones. My wireless Logitech MX Master mouse also works fine, as does my USB WiFi dongle. I received a system with a 7250 Xeon Phi CPU, so it actually has 68 cores and 272 threads. It does 1080p (1920x1080) via the VGA/SVGA port, and the display quality is excellent.