Forums › Life › Computers, Gadgets & Technology › whats a good ready made desktop computer these days?
Yeah the reason you get the IRQ problems is to do with the increasing need for more IRQ’s channles over the years … as they tried to go above 16 IRQ’s or something by doing the same thing they did to get it from 8 IRQ’s to 16 IRQ’s (doubling up on PIC’s) and it just wouldn’t work. It’s got something to do with “Legasy” being ingrained so much into computor stuff that EVERY thing after has to be backwards compattable otherwise nothing will work.
What they did, instead of doubling up what ever it was that they doubled to alow the systems to work with 16 IRQ’s, is make fake Virtual IRQ’s that have devices assigned to them and then they in turn are assigned to one of the original 16 IRQ’s. You can have more then one virtual IRQ assigned to a physical IRQ (there way around the problem of not being able to make more physical IRQ’s without totaly reworking the way computors comunicate with the processer) and this is where you get the conflicts cropping up as you potentialy have two devices trying to tell the processer to do something at exactly the same time.
The fact that window, using “APIC”, assigns the IRQ’s since xp (and not allways very well) is a massive problem to anyone working with computor stuff as I’ve searched for a way to force windows to not do this and there’s really not much you can do. You can’t turn off APIC anymore as computors have got more complex and relly on this workaround so much they litteraly cannot function as they do without it anymore. The people in charge of making the desisions on this stuff seem to refuse to take the leap and rework/scrap the legacy system (Intell I think forced their APIC architecture on every one else at some point, and after AMD’s version totaly failed they also started using intel, their compettitors, version!). It means starting afresh with the whole design of the way computors work (actualy afaik there are allready alternatives that have been developed, but you know how companies are with pushing their products – and intell have alot of power in the game).
You’ll find alot of the time it’s explained as “there were problems with compatability before APIC and it was designed to fix that”, which is partly true, but the reason it had to be invented is because of what’s underneath it, your oldskool 16 IRQ channles not being able to cope with the growing amount of things needing to comunicate with the processer, which can’t physicaly be expanded to handle the need for more interupt requests. They are trying to force the most out of 16 IRQ channles with a system to deal with more Interupt requests but using the same amount of IRQ’s, and alltho it does work to an extent, there’s only so many requests you can send down 16 channles before they become too crowded. If they “manned up” and changed core way it worked I’m sure they would run into alot less compatability issues, baring backwards compatability from that point ofc.
Yep I’ve noticed this on Linux as well, although you can sometimes stop “real” interrupts being shared by shifting around which slots the cards are put in.
I’m not sure how you do this on Windoze,
Here is a newer machine used as part of a telephone system. wctdm is the special card which connects to the British Telecom lines and samples them 8000 times every second – it is basically a special kind of sound card which connects to telephone lines, so as you can see it takes a lot of interrupts.
root@*******:~ $ cat /proc/interrupts
CPU0 CPU1 CPU2 CPU3
0: 916705296 0 0 59995 IO-APIC-edge timer
8: 0 0 3 0 IO-APIC-edge rtc
9: 0 0 0 0 IO-APIC-level acpi
66: 66 0 69 106 IO-APIC-level ehci_hcd:usb2
74: 4064 0 2226111 0 PCI-MSI ahci
82: 151 0 0 15023234 PCI-MSI eth0
169: 0 0 1019363 43382 IO-APIC-level ehci_hcd:usb1
177: 0 916705717 0 30161 IO-APIC-level wctdm
NMI: 0 0 0 0
LOC: 914837599 914837384 914837576 914837543
ERR: 0
MIS: 0
And an older one (single core Celeron) where I managed to turn off APIC in grub.conf. And I also had to turn off ACPI (power management) or the CPU fan ran at half speed until the damn thing overheated! I also lost some useful features such as power management. you can still see there are loads of interrupts, and they have to be synchronised to a very accurate time source or people will complain there is crackles and interference on the telephone calls. (This was also why I have been building that clock, which coincidentally also uses interrupt driven code!)
root@*******:~ $ cat /proc/interrupts
CPU0
0: 1268947191 XT-PIC timer
1: 8 XT-PIC i8042
2: 0 XT-PIC cascade
3: 1267693683 XT-PIC wctdm
4: 363352162 XT-PIC serial
5: 7 XT-PIC ehci_hcd:usb1
6: 5 XT-PIC floppy
7: 0 XT-PIC uhci_hcd:usb4
8: 1 XT-PIC rtc
9: 30528426 XT-PIC eth0
10: 0 XT-PIC uhci_hcd:usb3
11: 0 XT-PIC uhci_hcd:usb2
12: 4 XT-PIC i8042
14: 25593837 XT-PIC ide0
15: 254132432 XT-PIC ide1
NMI: 0
LOC: 1266303905
ERR: 0
MIS: 0
@General Lighting 447613 wrote:
Yep I’ve noticed this on Linux as well, although you can sometimes stop “real” interrupts being shared by shifting around which slots the cards are put in.
I’m not sure how you do this on Windoze,
I belive in some cases you can do this in windows, also reinstalling the drivers can sometime change the IRQ, but it doesn’t seem to want to work on my machine with the cards I have unfortunatly.
@General Lighting 447613 wrote:
they have to be synchronised to a very accurate time source or people will complain there is crackles and interference on the telephone calls.
This is exactly the problem you get with sound production if you have a conflict. Crackles, pops, interfearance and even total dropouts for split seconds. In worce case senarios it can actualy lock up the entire PC for a bit!
Asio timecode controlls the synking of midi and audio in DAW’s and if this isn’t synking properly again you’ll get the same problems with the sound.
TBH looks like I might wait until next year to do this PC upgrade – as I won’t be able to afford that and extra audio kit at the same time. I’ve just about managed to get my existing kit to play nice (well some of the time) with editing 480p content (DVD quality) and my current camera is still the one I got back in Reading and only standard definition (it still uses MiniDV tape and 1394 connection!).
If upgrade my video kit I would be looking at something like this (3CCD but still relatively compact)
Camcorders – HD Camcorders – HDC-SD900 – Overview – Panasonic UK & Ireland
but its full 1080p/50 and that is gonna need a serious computer to handle that sort of video.. 8GB RAM, 64 bit OS and accelerated graphics card (will be running it with two dual head widescreen monitors as well) – but all this certainly isn’t gonna be cheap so will need to save up for it…
Firewire is actualy faster then USB … alot of pro audio stuff uses it nowdays.
@DaftFader 453170 wrote:
Firewire is actualy faster then USB … alot of pro audio stuff uses it nowdays.
when I first got into digital video editing there was only usb1.1 anyway and firewire predated it.
to be fair its a good and robust way of transferring data, its just a pain having to wait for the capture to happen in real time from tape – with these new cameras it seems all you do is put the card in a reader and copy the video file straight across…
will probably need another terabyte for video (I really ought to capture every one of my old DV tapes properly before the magnetic coating starts to deteriorate). The problem I find though is that a huge AVI file (such as the entire contents of a tape at 60 minutes) is a real pain to try and load into most editing software so I tend to do the captures in 5 to 10 minute chunks of the footage (which is more time consuming at the first stage)
I also need fast speed for conversions as I often get content from anything from phone cameras to camcorders with a big variety of resolutions and aspect ratios…
still way better than the analogue days of editing with video cassette recorders though…#
@DaftFader 453170 wrote:
Firewire is actualy faster then USB … alot of pro audio stuff uses it nowdays.
the drawback to use sound gear through a firewire connection is that it will block for a daisy-chain is my experience. The controller and mix board consequently drops out when other added hardware kicks in….and that U cannot use if U at the same time want to use the firewire for synchronize(to external-drive) or mirroring of primary, studios will normally have a computer dedicated for sound then it will be no problem with firewire because U simply do not daisy chain.
Personally I would step back and wait for a while because USB3 and thunderbolt needs some more time to kick inn(both for price and the number of gear that exist on these standards), those connection-platforms means giant step forward in speed, then you get speed…high speed transfer
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Forums › Life › Computers, Gadgets & Technology › whats a good ready made desktop computer these days?
