External vs Internal Hard Drive Speed 4

[TheRogueWolf]

Hi, I'm new to this forum so please excuse me if this is a stupid question.

I'm trying to capture video from an analogue source to my laptop using a Belkin Hi-Speed USB 2.0 DVD Creator but without much success. I can capture at full PAL resolution to my desktop PC with no loss of frame rate but capturing to the laptop results in dropped frames and jerky video.

After doing some research on the net I found that the laptop only has a 4700 rpm hard drive and I'm now fairly sure this is where the bottleneck is occurring.

My question is: I have a Western Digital MyBook external hard drive with both firewire and USB 2.0 connections which runs at 7200 rpm. Would this be faster than the internal hard drive taking into account the fact that it is connected externally?

Many thanks!

 

[wahnula]

TheRogueWolf

Hello and welcome. While I am not an expert on video capture/recording/editing etc., many members here are. I think the hard drive is way down the list of suspects in this case, but I have been wrong before. Yesterday, in fact. The CPU, chipset and RAM are probably the culprits here, with video chip (part of the chipset) included.

4700 vs 7200 means faster read/write times, but the data pipe is still the same size and it should be plenty big for video. I don't think an external drive will help.

What are the laptop specs?

Tony

 

[TheRogueWolf]

Hi Wahnula, thank you very much for your reply.

The laptop specs are as follows:

Sony Vaio VGN-T2XP
1.20 GHz Pentium M CPU
512 MB shared RAM
60 GB Hitachi Travelstar HDD (4200 RPM)
MS Windows XP Pro SP2

I'm not sure how much work the CPU, memory and video components are having to do when I'm capturing the video. The reason I thought the HDD speed was a major factor is that, as far as I can tell, the Belkin device is handling the conversion internally and spitting out digital video and audio in real time. Judging by the size of the resulting MPEG files when capturing in full PAL resolution of 768x576 at 30 fps I would say that's a lot of data per second. I've also been wrong many times before though!

 

[wahnula]

Check your DMA setting: right-click My Computer->Properties->Device Manager->expand IDE ATA-ATAPI->Properties, right-click Primary IDE->Properties->Advanced Settings->DMA if available.

Your laptop should be able to handle the job. I would recommend more RAM for video work, at least 1 GB. If the HDD is the bottleneck, you would be better served to replace it, not use an external. Even at max USB 2.0 speeds (480mpbs, but it never reaches that speed) IDE or EIDE will be much faster.

You should first upgrade RAM and see how that goes.

Next, I would consider replacement of the stock HDD w/ a Hitachi 7200 rpm TravelStar. Clone your disk via USB to the new drive in an external case using Acronis TrueImage or Ghost, then swap drives. Your old HDD will be a new external backup drive.

There will no doubt be others with differing opinions, probably by the end of the day.

Tony

 

[stduc]

Just a thought - have you defragged the drive lately? But apart from the possibility the drive is badly fragmented I would agree with all of the advice above.

[navy]When I married "Miss Right" I didn't realise her first name was 'always'. LOL[/navy]

 

[cdogg]

I'll throw my 2¢ out there...

First of all, USB 2.0 maxes out at 60MB/s (or 480mbps) which is not a lot of breathing room for even the slowest hard drives. While it's true that most hard drives made within the last 3-4 years average 45-50 MB/s, they can easily peak over 75MB/s. Without the peaks here and there crossing 60MB/s, the average drops significantly.

This is why I would think a USB 2.0 drive would struggle to outperform a laptop's 4200RPM drive. And keep in mind that although the RPM's are lower, that doesn't necessarily mean slower transfer rates. Realize that laptop drives are much smaller to begin with and use higher densities on each platter. Therefore, less speed is needed to read the same amount of data in comparison.

But yes, most 4200RPM laptop drives struggle to break 40MB/s transfer rates. Even so, capturing DVD-quality video in MPEG-2 format should take up less than 10MB/s of that bandwidth. So in other words, your problem shouldn't be the drive unless it's failing or heavily fragmented.

What kind of video capture device are you using? Is it external or built into the laptop?



~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[wahnula]

cdogg,

I can capture at full PAL resolution to my desktop PC with no loss of frame rate but capturing to the laptop results in dropped frames and jerky video.

So the issue is...what is the difference in the PC and the laptop (besides HDD)? RAM. I'll bet the desktop has more RAM and a discrete GFX card.

Tony

 

[TheRogueWolf]

Thanks for the great replies guys.

@Wahnula: I've checked the DMA setting in Device Manager and it is set to 'DMA if available'. You're right about the PC being much higher spec than the laptop. It's got 2GB RAM and dual Nvidia 7800 GFX cards, it's also got a much faster, dual-core CPU. Unfortunately the PC is upstairs and the device I want to capture from is downstairs with no option to move either :-(. Just out of interest, is the GFX card actually involved in the process of capturing video? I would have thought not (other than to display the preview while capturing takes place).

An additional 512MB of RAM is about £52 (about $100?) so I'd want to be fairly sure that would improve the situation before upgrading. Would it be worth running a capture with Task Manager open so I can see the load on the RAM/CPU? I don't think I have the option of upgrading the internal HDD, the laptop is an ultraportable with a 1.8" drive and there doesn't seem to be any way of getting at the drive short of removing the bottom of the laptop case. I'll do a bit of googling and see what I can find on that one.

@stduc: The drive contents were somewhat fragmented so I've run defrag to see if that helps. Unfortunately I'm away from home at the moment so although I have the laptop with me I can't actually test any of this yet. Very frustrating!

@cdogg: The capture device is a Belkin Hi-Speed USB 2.0 DVD Creator which is external and connects via USB 2.

 

[stduc]

Personally I wouldn't just throw money at the problem until I had tried everything else I could think of first.

So, before you get more RAM - which may or may not solve the issue, make the most of what you have.

I suggest you do use taskmanager to see what is going on. Turn on extra columns and look at memory usage. Sort tasks by CPU and also my memory usage while capturing. Also keep an eye on page file usage.

Set your own pagefile, don't let windows do it for you. Defrag repeatedly until no improvement in time to defrag. Remove the pagefile, re-boot, defrag again, then create a fixed page file of 1.5GB. That way the page file is not and never will be fragmented and will be as efficient as possible.

Don't run anything else while capturing - so no email programs, MSN messenger or anything else.

Finally, stop all services you don't need. See this article

http://www.jasonn.com/turning_off_unnecessary_services_on_windows_xp

Specifically, ensure that you are not running the indexing service.

If the laptop is not on the internet while capturing, you can safely temporarily stop all anti-malware software - anti virus and anti spyware.

Keep an eye on available memory in task manager to see how you are getting on. Make a note of what it is before you start (i.e. now) and after you have stopped all services you can. You may be surprised at how much RAM you can reclaim. (Start task manager immediately after booting and note the situation then so you have a sort of benchmark)

I hope this helps.

[navy]When I married "Miss Right" I didn't realise her first name was 'always'. LOL[/navy]

 

[cdogg]

Keep in mind too that there are a lot of other factors besides the "amount" of RAM. For example, your desktop uses a "dual-channel" configuration for the memory, which doubles the amount of bandwidth. It probably uses faster RAM as well.

But what you should focus on is available resources. stduc is right about spotting and disabling resource hogs. It only takes one, though it can be a tedious process trying to find it. Task Manager doesn't always make it obvious.

Also, you want to check your Power Management settings. On the screensaver tab, click "Power" at the bottom. Check the name of your Power Scheme (I used Portable/Laptop below).
Then go to Start -> Run and type cmd. Click OK. Type the following at the command prompt and hit enter:

powercfg /change "Portable/Laptop" /processor-throttle-ac NONE

Running this command disables speedstepping on your processor when you are plugged into AC power. Make sure you replace "Portable/Laptop" with whatever power scheme your laptop is using. It won't give you any confirmation, but you'll know it went through if there isn't an error message displayed. I've seen many cases where a laptop runs at half or a third of its speed for too long before finally kicking into 5th gear (and I'm not talking about when the laptop is idle). Speedstepping is nice when you're on battery, but unnecessary when plugged into a wall outlet.


And finally...
The device you're using to capture video is doing a quick coversion from analog to digital, but the format is still raw when it gets to the computer. The conversion from raw to MPEG-2 (or whatever format you're using) is going to be mostly CPU and RAM intensive. The only time that's not the case is when you have a specialized video card (such as a Matrox rt.x100) that can do the conversion internally with built-in hardware. Those cards aren't cheap either. So the moral of the story is that the hard drive and video card you have aren't much of a factor here.


Unfortunately, I don't think there's going to be a single magic fix. It's probably a combination of things above...


~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[TheRogueWolf]

Thanks again for the advice. I'll do all of the things you have both suggested tonight. I am tempted to get the RAM anyway as even if it didn't resolve my problem it would undoubtedly speed up the laptop in general.

I think you're right cdogg, it's probably going to be a case of trial and error. Thanks for the info on raw vs MPEG output, I hadn't realised that.

Just as a thought, could I run 10m long S Video and audio leads or a 10m long USB cable from the source to my PC upstairs? The Belkin device is USB-powered so I'm not sure if the USB cable would be too long.

 

[Nelviticus]

Long video & audio leads won't be a problem if you use good ones (although the signal will probably degrade fractionally) but 10m long USB cables will. It might work and it might not - USB is supposed to be limited to 5m, anything over that could be very flaky if it worked at all. Apparently you can use hubs or repeaters to achieve long USB links but long AV leads would be less hassle.

You said at the beginning that you had a MyBook external drive with firewire and USB connectors. If you try that, use firewire - there is more CPU overhead when you use USB and you're already shoving a lot of data over the USB bus.

Regards

Nelviticus

 

[TheRogueWolf]

Thanks Nelviticus, I'm going to try the MyBook via firewire as soon as I get back home next week to see if bypassing the internal HDD has any effect. From what the posters above have been saying it doesn't sound likely but at this stage anything's worth a go.

I've already got a 10m S-Video cable so I can try a 'without sound' test as soon as I get home. If that works it won't be ideal but if I can't get the laptop route to work it might be my only option.