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Sugesstions to get CPU down from 95%


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I have a rather high CPU usage when watching HD content both BBC HD around 35 - 40 % Prem HD and Discovery HD at around 95 % and lots of stutering on this channel. For an experiment I got my TM9100 tuned into BBC HD and then watched the stream via VLC, the CPU usage is around the same as when watching through the TT budget card/DVBV.


I have read on this forum that others also have something similer with some intel graphics cards, my system is a Asus p5e-VM HDMI board with the Intel G35 graphics chipset running the latest drivers.


My CPU is a dual core Intel E8500 which is a decent processor so I am thinking at the moment the only solution would be to buy a graphics card of some sort that would give some relief to the CPU.


Does anyone have any opinions as to the best way I can improve the performance here?



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start -> programs -> DVBViewer program group -> support -> DVBViewer (safemode).

Does it work then?



Still works and the CPU usage is the same. I think the problem is with the G35 graphics chipset, as I have the same CPU usage when I stream the BBC HD as when using DVBV Pro. I also get a similar usage when watching Blu-Ray DVD. Just with the S2 transponders then the CPU is higher again.



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Are you sure that the G35 supports some H264 decoding?

DXVA enabled? If not then the CPU does the decoding.


Record a DVB-S2 stream and play it aferwards, still high CPU load?


I had to disable the I945 video controller and install a better card, in our case a ATI HD3470

and CPU load on S2 floats around 13% on a dualcore pentium mobile T2500 2Ghz


The ati switches to 700Mhz clock on S2 , drops to 300Mhz playing normal content.


Your problem could also be related with software. Avoid too many codec's.


Post a support.zip file.


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Thanks for the reply.


I am not sure if the onboard graphics support all h.264, I will record an S2 stream as you suggested and see what it's like. I am away until the weekend so won't able to do much until then. If it is the fact I could do with buying a graphics card with HDMI would you recommend a particuler one?



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Both nvidia and ATI/AMD have video cards that support H264.


I use the ati cause Nvidia has a weird way to handle digital encrypted video

which leads to a few % more CPU load.


I did choose a HD3470 but any HDxxxx will do the trick starting from HD2400


On nvidia's side, no idea cause I left nvidia.



The G35 uses the intelX3500.

This videoprocessor decodes mpeg2 very good, but any card can do that these days.


The videoprocessor can play H264 content but it only supports H264 HW motion compensation.

and not Inverse transform and variable lenghts decode so leaves more to the main processor.


DXVA also know as hardware acceleration schould be enabled before the videocard will help

with H264. If hardware acceleration is not activated then you need a real fast processor not under

3,2Ghz and dual core.

Edited by Benarty
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Intel G35 does not help with h264 very much. I think the new G45 with 4500HD kernel will help decoding h264.




I have asus P5E HDMI that is also based on G35


I have Duo Core 3Ghz latest rev.

I struggle with jerky picture on SVT HD beacuse they have a frame rate of 50 fps and i only get about 44 fps

/view/filters/evr will give this info

cpu load about 38% on both cores using coreavc 1.8

TT S2-3200


Also make sure you disable the dynamic cpu speed switching



run cpu-z info to se if your multiplier keeps toggling and thus the frequency.


At any rate it still is jerky at 38% cpu load so problem is bandwdith to memory from S2-3200 over pci or bandwidth to G35 chipset or innternally in G35.

G35 chipset has been a disapointment this far also considering the driver bug that wont decode colcor correctly with vista evr renderer.


My hunt continues.

SVT HD is 1280x720p 50fps 17.3 Mbit/s -> 20.3Mbit/s 38% CPU @3Ghz Duo

ASTRA HD+ is 1920x1080i 25 fps varies between 4.2Mbit/s -> 17.x Mbit/s about 10-38% Cpu load.


Astra needs deinterlacing but to turn this on at the coreavc makes it more or less stop.


If its the higher bitrate that is a problem for the PCI bus i will try to hike the PCI bus frequency in BIOS from 33Mhz and see if it helps.


What does annoys me is that this is a big problem for

so many people, still I cant find much help from the professional side, from thoose who works with this all day long.



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I've got the same motherboard and I struggled with it for ages. I have ended up getting an ATI HD3450 512MB which is the best cost effective passive cooled solution that I found at the time. I do think that the G35 doesn't live up to the marketing. The marketing certainly implies HD 'with ease'.


Two things to try...


1. Turn off the remap memory feature in the BIOS. For some reason this made my G35 run at snails pace.


2. If you can, vacate one of the PCI-E slots or swap the card to the other slot. The G35 video is tied in with the PCI-E slot and runs poorly with my video card in. I assume a similar effect with a tuner card. I don't know the exact details of this.


Just for extra information. I was running a RAID-0 but this causes glitches where the computer and mouse will pause for a second and the audio will click or repeat a sample. I changed the set up to 2 disks as per 'normal' and it runs like a dream. I would much prefer the higher bandwidth that the RAID-0 provides and my motherboard was sold as doing :blush: but when you get it working...


I have speedstep switched on and the settings in the power 5%-100%. CPU load with BBC HD is 23-26%. Although I'm not now running the Asus probe software (it crashes when you go away for the week), the CPU was at 30-35 deg C when tested while watching HD. (Antec Fusion case. 2 case fans. No CPU fan.) (Q6600 "Energy Efficient SLACR 95W Edition" )



Edited by Dennis_too
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Lot's for me to try out :blush: it does look as if getting a decent graphics card is going to be the way forward for those troubled S2 transponders, which is a bit of a shame as the onboard HDMI was the main reason for buying this ASUS board to begin with, but then again that ATI HD3450 card is under £40. What is strange is the BBC HD runs at about 35% CPU and the bit rate is quite high 16mbps or so and is great.


The S2 transponders have a similar bit rate but the CPU is double, is this due to frame rate or something else?



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Thanks for the info,


The TT S2-3200 is in the legacy PCI slot, not in PCIe (I wich they where for PCIe but they are not).

Dont know if it runs 33Mhz or 66Mhz, another mystery.


I bought the ASUS P5E VM HDMI as a replacement for the Fata1ty HD90 based on ATI 1250


G35 is a complete fraud, hyped as a stellar perfomer for 1080 but performs worse than the much older ATI1250


Also the colormapping bug inte G35 driver makes it useless.


Another thing that everybody has problem with is that driver changes resolution and/or turns off audio if you turn of TV or boot with TV off...

If you have a HTPC with a TV over HDMI its not as if you randomly changes the TV set.


I mean gosh ,, how hard can it be to fix that ???


So this motherboard will go back.



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Presently, the NVidia 9500GT is definitly the best buy.


It is cheap and easy to find it in fanless version.


The Purevideo HD second gneration is included. It's means there is one separate dedicated circuit for hardware H264 decoding. Associated with the Cyberlink H264 filter, the result is perfect+CPU load very low.


In addition, there are few interesting HD picture enhencements.

Edited by trifon33
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I ran of and bought the ATI 3450 but only with 256Mbyte of memory.

I can say that it runs a little bit faster than intel G35 but not much.


Problem is the SVT HD at 50fps, its a killer.


The 25fps HD channels is a walk in the park.


The 3450 can after a while reach 50 fps, but the funny or not so funny thing is that as soon as it reaches 50fps, the picture goes black for 2 seconds then comes back, starting from 0fps goes rapidly to 44fps than within a minute or so it reaches 50fps, but in the very moment it reaches 50fps the picture dies.

Very odd. This is with the Vista renderer, running EVR9 does not happen this but then frame rate goes up to only about 46fps.


Conclusion, 50fps is not something G35 or 3450 can manage easily, on top of that there is some bug in renderer or driver or something that kills the picture when you break througt the 50fps wall.


25fps streams are rock steady at 25.002fps


Next step ?, maybe the 3650 passive cooling.


Satellite watching is not a mass-market, if it where this should have worked years ago.



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  • 2 weeks later...


Presently, the NVidia 9500GT is definitly the best buy.


It is cheap and easy to find it in fanless version.


The Purevideo HD second gneration is included. It's means there is one separate dedicated circuit for hardware H264 decoding. Associated with the Cyberlink H264 filter, the result is perfect+CPU load very low.


In addition, there are few interesting HD picture enhencements.


My CPU usage hovers between 1 & 5% when watching BBC HD. I have an Intel E8400 2 Gig of RAM and an Nvidia 8800GT 512Mb G/Fix card. I know that card is too Big, too hot, too Noisy and too power hungry for HTPC's but just thought I'd add to the benefit of a decent Graphics card for decoding HD. It also handles Bluray discs very well and is HDCP compliant.

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  • 2 weeks later...

My ATI 3650HD runs at 60%ish with BBC HD i've read somewhere that it's core avc that doesn't use DXVA ???

To be honest tho all the other codecs run crap on my system in comparison! Inc.. PowerDVD 8

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