performance difference between two same-model notebook PCs - possible factors?

Recently my Dell XPS M1330 notebook PC spent two weeks in the Dell repair unit due to GPU failure and in the interim, I used my brother-in-law's notebook PC, which is the same model, but with differences in some key components. From this point, my PC is M1330-1 and my brother-in-law's PC is 1330-2. I noticed that M1330-1 is faster, particularly in turn-around time when watching .avi videos with Windows Media Player. For example, I'm watching video A, decide to stop it and watch video B. With M1330-1, I can stop video A and double-click the mouse on video B immediately afterwards, and video B "spools up" and plays almost immediately. With M1330-2, when I perform the same sequence, I have to wait 5-10 seconds between stopping video A and double-clicking video B in order to watch the latter. If I try playing video B sooner, it simply does not appear and I have to double-click on video B again after the 5-10 second latency period for it to play. I have compared this playing video A and video B off the same external hard drive connected to M1330-1 and M1330-2 via USB 2.0.

The key components of the two PC's:

M1330-1: CPU - Intel Core 2 Duo T9300 (2.5GHz, 800MHz, 6M L2 cache); RAM - 4GB, DDR2, 667MHz 2 DIMM; Hard drive - Seagate Momentus 7200.3 320GB, 7200 RPM; GPU - nVidia geForce 8400M GS.

M1330-2: CPU - Intel Core 2 Duo T8300 (2.4GHz, 800MHz, 3M L2 cache); RAM - 4GB, DDR2, 667MHz 2 DIMM; Hard drive - Western Digital 320GB, 5400 RPM (exact model not known, original hard drive installed by Dell); GPU - Intel Integrated Graphics Media Accelerator 3100.

What accounts for the significant difference in latency time in changing video A to video B between the two PC's? I know it's probably due to the combination of the faster hard drive and faster CPU in PC M1330-1, but does one component play a larger role than the other? I know this is possibly (probably?) a trivial query, but it may help me better understand the functions of various hardware components.

Thanks,
PG

 

With a 5-10 second delay after stopping a video, I would most likely guess that this is a software issue instead of a hardware one. Your computer has less (or less intensive) background processes than your brothers, and thus more processor cycles can be dedicated to the video. However, obviously the hardware differences play a part, but shouldn't lead to such a pronounced effect on processing speed.

 

The only thing I can really see that would make a difference is the graphics card and possibly the software running in the background. Maybe the 1330-2 has more background processes or a different codec than the 1330-1.

 

... and the fact that he has a 7k320 in his machine as opposed to the 5k320 in his brother's. Pulling the file down from the HDD is going to be faster on the faster drive, of course. But yeah, not 5-10 seconds, I'd think. I wouldn't think the GPU would have much impact though, since other than hardware decoding (which I'm pretty sure even the IGP does decently), it won't be making a contribution here.

 

He states that he has seem similar results when viewing the file on both computers from an external hard drive, which is why I ignored the difference in internal hard drive speed.

Unless that makes a difference in this case?

 

I would say it's a combination of harddrive and software. Even if the file is on the external HDD the system files which need to be accessed are on the main HDD and they are probably causing the lag. Again this is just a far out guess. Also in general moving from a 5.4K to 7.2K harddirve is quite a decent performance boost for most machines in terms of snapiness. Also depending on how properly defragged and junkfree the system is better the performance. I think both these factors combine to give the end result.

The original poster is not doing anything Graphics Card intensive, so i would probably rule that out. Processor wise they are similiar enough to be negligible.

again this is just a broad guess and should be taken with a grain of salt.

 

I would say software, OS and/or drivers. The difference seems too large to be attributed to the difference in hard drives. There's little between Seagate 7200.3 and WD3200BEVT performance. The CPUs are also quite similar (except the cache). That's why I think software related.

How many processes are running on both PCs? (ctrl-alt-del)
Have you tried different video players?

Maybe it's the difference in cache though. 3MB vs 6MB is a large difference, and maybe this one of the only moments that it really shows.

 

Thanks for the responses and opinions. Both M1330's have roughly the same number of processes and software, with the exception that mine (M1330-1) has the MSN Office Suite Student edition and my brother-in-law's (M1330-2) does not.

Phil suggested that the increased cache (6MB vs 3MB) might be a factor and I'm starting to suspect this as well. I had also suspected my faster drive would be a factor, but the consensus on this thread suggests not. Anyway, thanks again, all of your responses are quite helpful.