mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > Hardware > GPU Computing > GpuOwl

Reply
 
Thread Tools
Old 2021-06-26, 22:46   #23
Uncwilly
6809 > 6502
 
Uncwilly's Avatar
 
"""""""""""""""""""
Aug 2003
101×103 Posts

980210 Posts
Default

Quote:
Originally Posted by drkirkby View Post
Yes, but Canada, USA and South America on similar(ish) timezones.
You missed the point, we have folks outside that area. They can answer your question if they choose. But, I suspect they have chosen not to, because of your track record. BTW, USA and Canada together have time zones currently spanning 7 1/2 hours.
Quote:
The position in the queue only got swapped for another category 0 exponent assigned the same day.
Why not just leave the assignments be.
Quote:
BTW, I completed a triple check of one of the LL results you listed in another thread - M57906071. No less than 7 people got assigned LL tests, with 3 results, but at least two of them now agree.
Did you post in that thread that you were taking the exponent? Or is your queue so short that you were assigned it and it was completed in less than 24 hrs? It wasn't assigned when I updated the list with new exponents and you were not assigned it then. The result came in less than 24 hrs later.
Uncwilly is offline   Reply With Quote
Old 2021-06-27, 02:15   #24
drkirkby
 
"David Kirkby"
Jan 2021
Althorne, Essex, UK

11·37 Posts
Default

Quote:
Originally Posted by Uncwilly View Post
You missed the point, we have folks outside that area. They can answer your question if they choose. But, I suspect they have chosen not to, because of your track record. BTW, USA and Canada together have time zones currently spanning 7 1/2 hours.
Why not just leave the assignments be.
Did you post in that thread that you were taking the exponent? Or is your queue so short that you were assigned it and it was completed in less than 24 hrs? It wasn't assigned when I updated the list with new exponents and you were not assigned it then. The result came in less than 24 hrs later.
1) Both axn and kriesel answered my question. kriesel was kind enough to do a better P-1 test for me.

2) Delaying the start of an exponent seemed quite reasonable, as I had some concerns about how the P-1 was performed. Had kriesel found a factor, I would have unreserved the exponent.

3) I answered the M57906071 query in the relevant thread.
drkirkby is online now   Reply With Quote
Old 2021-06-27, 02:46   #25
drkirkby
 
"David Kirkby"
Jan 2021
Althorne, Essex, UK

19716 Posts
Default

Quote:
Originally Posted by kriesel View Post
For kicks, I put PFactor=0,1,2,103770473,-1,76,2 on a gpuowl run on Radeon VII GPU.
Do these Radeon VIIs have a reliability issue? A Google does not indicate a particular problem, but there are an awful lot on eBay for "parts only". Faulty ones are selling for 50% more than I paid for 26-core Xeons. No video output seems a common feature. If the faulty ones were a sensible price, I would be willing to take a chance and hope they worked for computational tasks, and not worry about the lack of video. But the prices are crazy for non-working items. $199 seemed cheap, until I realised that was only for the box!

These are out of my league.

Last fiddled with by drkirkby on 2021-06-27 at 02:47
drkirkby is online now   Reply With Quote
Old 2021-06-27, 04:05   #26
kriesel
 
kriesel's Avatar
 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

2·37·73 Posts
Default

The time to buy Radeon VIIs was about a year ago; new with 2 year warranty for $600-750 each. Later I picked some up used for about the same price range. Each Radeon VII, properly tuned with a good gpuowl version, can match PRP throughput of your $5000 dual-Xeon system; a 104M PRP / day. The case or mining style frame, a large PSU, a modest cpu and motherboard, a couple DIMMS, add maybe ~$100/GPU. Or more recently, a diskless Xeon Phi 7250 based system cost $700 used (years ago was ~$5k new). Some of us got lucky and the vendor shipped 7250s when we ordered $500 used 7210 systems. A pair of those provide PRP throughput about equal to your $5k system.

The current pricing for used working Radeon VIIs is remarkable. I've seen sales for up to $2400, 3-4 times new cost. This week was ~$1600. Broken no-display, no-OpenCL-compute, or even not-seen-by-the-OS (completely bricked) sell for almost original new price. Perhaps there are shops that can repair some fraction, given enough carcasses. Coincidentally, the manufacturer I have a pending warranty claim with is not repairing or replacing in-warranty Radeon VIIs, but offering either an RX5700XT (~45% of PRP or P-1 performance) or original-retail-price refund, which might buy 1/4-1/3 of an equal-performance GPU if we could find one in stock. (~RX6900XT)
kriesel is offline   Reply With Quote
Old 2021-06-27, 04:17   #27
LaurV
Romulan Interpreter
 
LaurV's Avatar
 
Jun 2011
Thailand

3·5·643 Posts
Default

They are used for mining (arguably, still the best card). People buy them, OC them, fry them, roast them, then want to sell them for more money than they bought them new. Don't buy, unless you know exactly what you are doing, and are willing to dirty your hands with soldering (and have the tools - a simple soldering iron won't do it, the substrate of that PCB is freaking dissipative, you will not be able, or will need ages, to heat it till the tin melts). Talking from own experience (working in an electronics factory).
(edit: we crossposted, I was replying to doctor).

Last fiddled with by LaurV on 2021-06-27 at 04:18
LaurV is online now   Reply With Quote
Old 2021-06-27, 05:38   #28
VBCurtis
 
VBCurtis's Avatar
 
"Curtis"
Feb 2005
Riverside, CA

28×19 Posts
Default

Quote:
Originally Posted by drkirkby View Post
Faulty ones are selling for 50% more than I paid for 26-core Xeons.
I think I'll start a count of posts where the famous 26-core Xeons are mentioned.

One.
VBCurtis is offline   Reply With Quote
Old 2021-06-27, 06:06   #29
Uncwilly
6809 > 6502
 
Uncwilly's Avatar
 
"""""""""""""""""""
Aug 2003
101×103 Posts

2×132×29 Posts
Default

Uncwilly is offline   Reply With Quote
Old 2021-06-27, 20:28   #30
kriesel
 
kriesel's Avatar
 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

2·37·73 Posts
Default

26... Is that considered a lot? I remember when I thought 12 was. Or dual-quad-core Xeon was a lot of cpu power. Or dual-pentium-mmx-200. Or 386-33 with two levels of caching (subsequently upgraded to a TI 486/66 core & Cyrix Fasmath coprocessor). Or 8 MHz NEC 70108 in an 8088's socket with the PCB of an original IBM PC solder-iron-hacked to split the clock signals out and put faster 74LS TTL chips in certain locations and overclock the base design ~50-60% while preserving the 14.31818 MHz /3 and /4 frequencies needed for IO bus and timing.
Attached Thumbnails
Click image for larger version

Name:	cpuz-win10-build1909.png
Views:	15
Size:	26.7 KB
ID:	25195   Click image for larger version

Name:	r7-gpu-z.png
Views:	18
Size:	29.7 KB
ID:	25196  

Last fiddled with by kriesel on 2021-06-27 at 20:30
kriesel is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Best type of work for lowest exponent work? cappy95833 Software 5 2019-11-21 04:24
Work Assignment Question Fred PrimeNet 4 2016-04-23 21:47
How can one prevent assignment of new work? Dorian PrimeNet 13 2012-04-11 21:52
How to calculate work/effort for PRP work? James Heinrich PrimeNet 0 2011-06-28 19:29
Old Assignment Primeinator PrimeNet 4 2009-06-04 22:35

All times are UTC. The time now is 08:07.


Wed Jul 28 08:07:24 UTC 2021 up 5 days, 2:36, 0 users, load averages: 1.70, 1.59, 1.56

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.