Does Hyper-Threading make only half of CPU to be used in ffdshow? Started FFDShow with 2048 X 2048 while wathching Speed Fan as well as Windows Task Manager. Both show CPU Usage as split into two where one is fully or almost fully loaded, while another one is hardly used. Total CPU usage is stated to be 48% - 53%. CPU temp 63C. Seems like only half of CPU is used for FFDShow activities.
How do I know CPU is fully used if both Speed Fan and Windows Task Manager show only 50% usage. When I started CPU stress program in the testing of the system period, it adviced me to open two windows of the same application and start stress simultaneously. I used Stress Prime 2004 for this purposes. Result was like this. When I have only one window of stress prime started, CPU monitoring show only one half of CPU fully loaded and total CPU usage is around 50%. However once I opened second window for stress prime, it increased usage of CPU to 100%. You can also feel that from PC responsivness.
If I draw parallel between provided CPU usage ratios in stress prime and on the other hand ZP+FFDShow I assumed that I am not utilizing total system capacity.
Can you select some option in ZP or FFDShow to force it to use 100% of CPU?
Some people adviced to see CPU performance under encodinvg. I tried encoding yesterday one file. Looked at CPU and it show close to 100% usage, so I came to conclusion that my CPU is fully loaded when encoding. Took abit more than 5 minutes to encode 4 minutes of video which also is quite high speed. I would be much longer if I used only half CPU. I did not try to encode 2 files at the same time. The point is that during ZP+FFDShow playback CPU monitoring software only shows 50% of usage and that corresponds to average of two graphs displayed, where one is close to zero, another close to 100% loaded. I could try to open two zoom players and start playback , don't know if that is possible. Then I could see if CPU is 100% loaded and if the picture is clear and smooth.
So I am still bewildered...
If Hyper Threading has to be swhitched off, do you know if I can just do that in BIOS, or do I have to reinstall Windows and all the programs?
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05-25-2005, 10:18 #1
PIV Hyper Threading and CPU usage under ZP + FFDShow
05-25-2005, 18:17 #2
Turned off Hyper Threading in BIOS. I think the picture is smoother now on 2048 X 2048 and is completely smooth on 1600 X 1600. So I suspect FFDShow is not using all CPU power once Hyper Threading is on.
Would be nice if somebody else could do the same experiment and give some feedback.
05-25-2005, 22:30 #3
ffdshow does not support dual cpu, so when ht is active it only uses 50% which is the same as 100% without ht.
05-26-2005, 11:26 #4
Didn't quite understand "uses 50% which is the same as 100% without ht". Do you mean that with 50% usage of CPU under enabled HT you can get the same amount of postprocessing done and get the same quality picture as with HT disabled and 100% CPU usage... ???
I find it hard to understand. 50% to me is half of the power. My CPU runs at 3,9 GHz, so once it is 50% used I understand it is only running at 1,95 GHz. Am I wrong?
As I mentioned, it looks to me that picture is smoother after disabling HT and using 100% of CPU. But it could be coincidence and my wishfull thinking. Since it takes time to do changes in BIOS and restart machine it might be I do not remember exactly what was the picture like...
05-26-2005, 14:19 #5Do you mean that with 50% usage of CPU under enabled HT you can get the same amount of postprocessing done and get the same quality picture as with HT disabled and 100% CPU usage... ???
ht creates a vitual second cpu
05-26-2005, 16:10 #6
Here is what I found on the net:
"In my first article, we noticed that during our DivX encode performance suffered when hyper-threading was enabled on both of our test systems. The performance decrease was in the neighborhood of 10-16%"
The rest of article could be found on
http://w w w .2 c p u.com/articles/42_2.html (not sure if I can post live links, please delete spaces)
Now then. FFDShow activity must be similar with encodind activity. Taking a lot of data from HD or Optical drive, manipulating it via CPU and sending out to HD or GPU. If you agree that FFDShow performed tasks could be compared to DivX encoding, then we could say that HT can reduce actually performance.
I am not trying to be difficult here... just want to find the best solution for HTPC and hopefully this thread will be usefull to others as well.
05-26-2005, 17:43 #7
i don't understand y but u might have something there!
i though that ht would help in applications that supported it and make no difference in applications that did not.
05-26-2005, 18:00 #8AMD says industry standard benchmark tests show that the Hyper-Threading does not provide consistent performance benefits on real-world desktop applications. Enabling
Hyper-Threading can even worsen a Pentium 4 processor’s performance by as much as 10% on some applications. In fact, the statement seems to be correct, since the Hyper-Threading does not provide benefits all the time and sometimes even reduces speed. We need to note that there are a lot of cases when the Hyper-Threading does provide benefits.
05-26-2005, 22:28 #9
I use the same PC for HTPC and for day to day tasks. I have setup two XP installations on different HD. This allows me to use one configuration for HTPC and another one for day to day operations. I would prefer to have HT enabled once I use PC for browsing, reading mail. Once I restart then it is better to disable HT. This is possible, of course, via BIOS adjustment. But that would be painful solution to enter BIOS everytime. Would be best to have some kind of .bat file. Best for me would be to have .bat file that would disable HT, would start PC restart procedure and also would indicate PC what HD it should start from, so that I would not need to sit and press F8 (this enables me to select bootable HD) continuesly. Is that a dream?
05-27-2005, 10:03 #10
yeah.. if u disable ht i bios and then load "htpc-mode" then u reinstall the cpu driver. so it says "ACPI single prosessor PC" under device manager.
then u enable ht again. now u will only utilize ht i "desktop mode"
05-27-2005, 12:48 #11
I tried to disable HT in the belive that it could give me better result on a htpc. But it was totally oposite. The cpu-load spiked to 100% almost all the time on mye 3.1 GHz P4. With HT on, I'm around 60-80% on a DVD with ZP/ffdshow. So that's that from me.Front: Klipsch IV RF62___________ Reciever: Yamaha RX-V1067
Senter: Klipsch IV RC62__________TV: Sony KDL-55HX855
Bak: Yamaha NS-300____________ HTPC: Sjølbyggd I5, Nvidia GTX970 etc.
Sub: SVS PC-12 NSD
05-27-2005, 20:53 #12
why do we write our answers in english? ajocius have told us that he understands norwegian Uansett så liker jeg bedre å svare på norsk.
Jeg håper ffdshow snart blir SMP siden vi nå har dualcore prosessorer. Jeg vil anbefale deg å sjekke innom www.anandtech.com for en GOD forklaring av hva HT gjør. Det er en forklaring der ,men den kan være litt vanskelig å finne og den er langt ifra ny.
Det er ikke slik at HT gjør at du får 2stk CPU`er på halv frekvens.. Bruker man bare program som støtter en CPU så får den ene CPU`en somregel mest resurser.. Men det er et tap i mange programmer ja
05-27-2005, 22:13 #13
Thanks for reply. Once you use HT, you mentioned it is utilizing around 60-80%. What kind go software do you use to check CPU usage? Is it showing only one CPU when you click on Ctrl+Alt+Del or two? But most impartantly what do you thing about picture quality compared to without HT? This could be better seen if you increase resize or other selections to load CPU with work and then compare. I write this because i find it strange, that it behaves different on my PC.
to CFD: yes i read Norwegian that is fine with me. It is just that I can not express myself wll enough in Norwegian. On the other hadn, both languages are not mother languages ....
Hope to fint the anwer if HT helps or not...... Curently disabled it.
05-28-2005, 00:46 #14
hehe.. fikk ikke meg meg at du forsto norsk jeg..
05-31-2005, 13:25 #15
Jeg har et Intel hovedbord og bruker Intel sofware for å sjekke CPU load og HT use. Med HT av går CPU load opp, så jeg har den derfor på. Bruker Zoomplayer m/ffdshow SSE2 utgave. Ingen forskjell i pq med eller uten HT.
05-31-2005, 21:52 #16
Thanks, what exactly Intel software do you use? Does it show one or two windows once you have HT enabled?
05-31-2005, 22:14 #17
05-31-2005, 22:21 #18
06-02-2005, 09:12 #19
Når man enabler hyper treading for ett program som ikke støtter hypertreading/multiptrosessering så vil det programmet(ffdshow) bare utnytte den ene treaden 100% ..noe vil også bli brukt av den andre prosessoren men det er da andre oppgaver.... sånn at det til sammen vil se ut som om cpu'en bruker 60-70% ....
Men med HT på vil dette føre til at ffdshow IKKE vil få tilgang til all prossesserings kraft og derfor være treigere med HT på enn av!
Velg derfor HT av hvis dere ønsker mest mulig kraft til FFdshow, Velg HT på hvis du ønsker å bruke pc'en til annen software samtidig!!
06-02-2005, 10:23 #20
gjorde en liten test i går å konklusjonen ble det samme som du sier! men vil nesten tro at det bortsett fra helt spesielle tilfeller er bedre å skru av ht og klokke opp litt ekstra.