I need to replace a dead computer that was more or less dedicated to capturing DVR playback and I'm looking for help in deciding what specs are most important in choosing the replacement.
Here are the details:
Well it finally died. My HP Pavilion DV1000 which was used to capture DVR playback through my:
FIOS Motorola HD QIP 7100-1 cable box via
S-Video into a
Dazzle 100 (DVC100 Rev 1.1) to the
USB port and then recorded with
Pinnacle Studio 12 with custom settings
MPEG 2, 720 X 480, 6000KB/S resulting in very roughly
1 GB / Hr recordings,
being used as video segments on a web page.
The HP laptop was apparently designed for video back in the day. I ended up with that box because trying to use one of my Dell GX270's resulted in frequent glitches in the recording, sometimes even when Studio was the only application running. That seemed strange since the HP's specs were:
512 MB Ram
50 GB HD w 14 GB available
266 MHz / PC211 CPU
Intel Extreme Graphics 2 Graphics Processor
XP SP03 OS
but it allowed me to at least run VLC to play back the recordings and a couple open windows of Win Explorer as well as the occasional Chrome session and still reliably recorded the Dazzle feed without glitches.
The Dells on the other hand have
3.25 GB Ram
50 GB HD w >20GB available
Pentium 4 Dual Core 2.8 GHz CPU
Either Nvidia GeForce FX 5200 (better) or the on board Intel 82865G Graphics Controller
XP SP03 OS
So it seems pretty clear to me that the specs for the graphics adapter are way more important than the CPU or memory since the Dells way outstrip the HP there.
My question is what criteria should I be looking for in the graphics on a new box to work at least as well if not better than the old HP did? Or are there other criteria to consider? Maybe I can just upgrade the graphics card in one of the Dell's?
Any suggestions or guidance is greatly appreciated.
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For SD capture? Just about anything current will do -- except maybe the Atom based boxes. It's always best to have two drives, one to boot, the other for capture.
Well, i wasn't necessarily planning to buy a current box. The last 3 computers I bought were those GX270's that are now available as refurbs for $50 or less. I'm willing to step up as necessary but would like to get in as reasonable as possible. New Dells seem to be over $300. Not anxious to shell that out if I can avoid it.
Am i right in thinking the graphics processor is the key to this? The more I think about it the less I'm so sure. But can't understand the discrepencies noted above otherwise.
So a good graphics card should work ok in my old Dells? What kind of spec should I be looking at?
How can I tell when the Sandy Bridge generation starts?
Thanks for your help.
I used to capture SD with an old nvidia 8600 gt card. Anything better than that should be fine.
For the nth time, with the possible exception of certain Intel processors, I don't have/ever owned anything whose name starts with "i".
As for SD capture, which is I think you're doing, any older computer you can get from the last 7-8 years would do fine if you wish to save money. Yes, multiple hard drives are important, and if it has multiple cores, which would not be impossible from this era, better still.
An old 2006 unit I have is used as a dedicated XP capture box, and runs just fine. Task Manager shows 30% average - anything less than 50% is very good.
Avoid laptops. They may have the specs, but likely to overheat and the result would be dropped frames.
I don't see what the big deal with graphics cards for this are, unless they are also capture devices. The graphics card on the mentioned device of mine burned out after only a year, and I've connected onboard since. I use only USB or firewire to capture (depending on source) and have been fine since.I hate VHS. I always did.
Thanks for the feedback PuzZLeR,
In the meantime I visited my local Microcenter and spent some time discussing the issue with a rather knowledgeable rep who helped me figure out the issue. I believe understanding the technical basis is always the most helpful in coming up with a reliable solution.
As I thought more about it I couldn't figure out how the graphics card might have an impact since I think the signal route is through the Dazzle into the USB bus and then to the system bus, ultimately to the processor. Once processed it then gets dumped to the drive.
Any clarification of the tech details here is welcome.
So what might impact the signal resulting in glitches?
1. The Dazzle is running on the USB, so activity there that perhaps impacts the power or data transfer might cause glitches.
2. Once on the system bus an over taxed processor might also lead to distortions in the data that might lead to video glitches.
3. Finally, an incapacity of the hard drive or HD controller to keep up with the data feed might also end up with video problems.
But from what i know 2 & 3 have buffering and fault tolerance systems to help them keep up with the flow. So I took a closer look at the USB bus, which I would also think must have some capability to adjust, but perhaps is the most susceptible to being overcome. And in my specific case it turns out to be the culprit.
In addition to the Dazzle I had 3 or 4 external USB Drives, a printer, a KVM switch and a SD Card reader on the bus. On the old laptop I had been using until it died I had only the Dazzle and a mouse. So I removed all the extra peripherals and ran a couple test recordings with no problems whatsoever.
One of those solutions which after the fact should have been obvious and a good example that no matter how much detail one provides in a problem statement it is quite possible that the most relevant information has been overlooked.
Thanks to all for your interest and help.
Keep in mind that a USB hub will slow to the slowest device connected to it. So if you have a USB 1.1 device connected to the same hub as a USB 2 device both will be running at USB 1.1 speed (12 Mb/s, not 480 Mb/s).
USB is a shared bus so multiple devices running at the same time may result in collisions that slow the devices down.
USB is also rather CPU intensive as it doesn't use Direct Memory Access (DMA).
Integrated graphics can be a problem because it usually shares DRAM with the CPU. Remember, the display is running all the time so the integrated graphics chip is accessing DRAM all the time just to show you the desktop. That can consume as much as 30 percent of the DRAM bandwidth. With a capture program continuously writing to video memory (so you can see what's being captured) a lot more DRAM bandwidth is being consumed. And if the program isn't using video overlay it must convert the incoming YUV video to RGB then copy that RGB to the display. So even more DRAM bandwidth and CPU cycles will be used.
Video capture is a realtime process. New video data is continuously arriving from the capture device. If the computer isn't ready to receive that data it will be lost. Even if CPU usage isn't pegged at 100 percent data may be lost because the CPU needs to be available when the data is. For example a CPU that is running at 100 percent for half a second, then 0 percent the next half second, alternating between the two, will show only 50 percent CPU usage on average. But if the CPU was busy doing something else during that 100 percent half second, and therefore not available to handle frames from the video capture device, it might lose 15 frames (at 30 fps).
Last edited by jagabo; 18th Feb 2014 at 13:20.
Excellent useful info Jagabo, and every answer raises more questions. I am using a video card (although a rather ancient Nvidia FX5200) instead of the onboard graphics, so that part is covered. Did not realize that any older device could slow the USB bus, good to know.
I also have the video preview turned off so the capture app (Pinnacle Studio 12) is not working that memory. But I'm wondering if there is a way to offload ALL of the video load on the CPU/DRAM? I could set up and start the recording and then do whatever it takes to shut down the video, if that is possible, and then after the recording is done reconnect the video, but is there a way to do that?
I need help understanding your reference to video overlay, etc. How might I determine if the program is or is not using that? And is that a problem only if the capture program is previewing the recording or even if it is not set to preview?
If I'm using the Performance tab in task Manager, is it responsive enough to tell me if I've avoided
topping out the CPU? It seems to update the graph about every second, so without doing the math it seems that if during recording it doesn't get too close to 100% it should be ok, although it's intrigueing to me that perhaps I could use that history to monitor for potential glitches rather
than have to review the entire recording every time.
Maybe you or someone can help me even better understand the USB issues.
This box has onboard USB, 8 ports (2 front, 6 rear) plus a USB 2 PCI card with 4 ports and I had a combination USB hub/card reader with 3 USB ports and 4 card reading slots which I have disconnected since last power up.
When I check Device Manager I see
Generic USB Hub - Location 0 (Generic USB Hub)
Intel(R)8201EB USB Universal Host Controller - 24D2 - PCI bus 0, device 29, function 0
Intel(R)8201EB USB Universal Host Controller - 24D4 - PCI bus 0, device 29, function 1
Intel(R)8201EB USB Universal Host Controller - 24D7 - PCI bus 0, device 29, function 2
Intel(R)8201EB USB Universal Host Controller - 24DE - PCI bus 0, device 29, function 3
Intel(R)8201EB USB Universal Host Controller - 24DD - PCI bus 0, device 29, function 7
USB Composite Device - Location 0 (HP Elite USB Keyboard)
USB Composite Device - Location 0 (2Port KVMSwicther)
USB Composite Device - Location 0 (DVC100)
USB Root Hub - Location 0 (same entry 8 times)
VIA Rev 5 or Later USB Universal Host Controller - PCI Slot 2 (PCI bus 2, device 8, function 0)
VIA Rev 5 or Later USB Universal Host Controller - PCI Slot 2 (PCI bus 2, device 8, function 1)
VIA USB Enhanced Host Controller - PCI Slot 2 (PCI bus 2, device 8, function 2)
So first question is, do the onboard USB and the PCI card USB share the same bus or not? In other words am I just as effectively isolating the Dazzle by putting it on the PCI USB card and anything else on the onbosrd USB (or vice versa) or do I need to keep both sets of USB as open as possible?
Secondly, if they can somehow cross impact each other, how can i tell whether my keyboard/mouse(which are connected via the KVM) are USB 1.1 or 2 or what?
And then out of curiousity, why are there so many more entries in device manager than the number of actual physical USB connections?
Thanks again to any and all for further input.
WOW! What excellent and helpful information. Always amazing how people are willing to take the time to share their expertise when asked. Thanks just seems to be inadequate.
Just a few clarifications if you have the chance.
Is there a way to shut down all video during a recording session and then restore it when done?
No advanced tab in my Device Manger Properties dialog.
Choosing Properites and then details gives me a whole list of info to choose from like
Device Instance ID = USB\\VID_03F0&PIC_034A\\6&21FC59&0&1
as well as Compatible IDs, Capabilities, Service, etc., but none that i can tell indicate which USB version.
You can reduce bithdepth in Windows desktop (from 16 million to 65 thousands colors or even to 256 colors - i.e. from 32 to 16 or even 8 bits - video capture will be not affected, you can restore 32 bitdepth after capture) - overall memory bandwidth should be increased and reduced latency, optimize your HDD, best is to have separate physical HDD not used by system (but software defragmentation is recommended anyway), use codec sufficient to deal with your CPU (lossless like HUFFYUV or comparable or lossy such as MJPEG), remove excessive software (autorun, system services - no you don't need server or remote access or fancy looking themes).
Last edited by pandy; 19th Feb 2014 at 11:49.
Thanks Jagabo & Pandy,
Jagabo, I think you mean "system DRAM is NOT used" here, is that right?:
I don't really understand the use of the codec in detail, other than to know it has to do with how the video signal gets encoded. I have Studio capture settings to Presets=MPEG-1/2, MPEG Type=MPEG2, Compression = MPEG Layer 2. If your reference to codecs means something other than that I'd need some help in how or where to find out how to config correctly.
Older motherboard with so called PATA is a different story - usually one controller have 2 channels, 1 channels is shared by 2 devices and usually slowest device limit overall channel performance, 2 devices on 2 separate channels should be in theory independent and there should be no performance loss.
If You can, try to buy even small HDD (however usually it will be slower than high capacity disk due transfer rate from plate - high capacity HDD have much faster internal transfer due density).
You can consider even to buy small SSD (32 - 64GB should be sufficient) for system with applications, TEMP and video storage can be on HDD.
I would advise to NOT use HDD on USB - as USB is serious problem for CPU, usually CPU load is very high for USB intense operation (interrupt or pooling in driver - both heavily occupy CPU) - USB is worst HDD interface especially when compared eSata or or even to firewire.
recording these digital streams in analog is so old school now, why can't you buy a dvb card (or atsc in usa), you can do so much paired with a good software such as dvbviewer.
- no quality loss
- low cpu usage (can run on an ancient computer)
- streaming over the web/local network possible
- set new recordings over the web, watch the stream on your android smartphone etc...