Is there a way to increase my internal HDD buffer. I have a few HD videos that have a higher bitrate than my hard drives buffer.
My first question is why do you think this is true?
I stream 1080p over wireless all the time... Wireless == roughly 5mB per second.
Now unless your hard disk is giving you a throughput of less than 5mB per second you shouldn't have any problem with it at all.
It's not about cache size, it's about SPEED.
One thing I noticed when I was trying Win7 on my HTPC was that it had really REALLY lousy hard disk speeds... My HTPC is an ASRock ION 330 with 500gb sata drive. Under win7 it tested in at burst speeds of 14mBps with sustained speeds of 9mBps. When I switched back to XP on that same machine the speeds went to 122 and 67 respectively. This slowness caused all kinds of havoc... MP3s would stop playing and the speakers would make this horrific BRAAAAAAP sound. Videos got out of sync, and stuttered, nothing worked right. When I switched it back to XP all those problems vanished.
Now I'm not saying you should switch to XP, I'm suggesting that if you're having problems with video and audio playback it's not your disk cache that's the problem... most likely it's the drivers for your hard disk not giving you the full speed capability of the drive.
If you go into hardware manager and look at your IDE/SATA controller (not the drive itself) you will likely find a speed test button... or you may need to engage a third party benchmarking program. In either case you need at least 20MBps of sustained throughput to play 1080p content (allowing for other processes that might be using the hard disk at the same time). If you aren't getting this, you need to look into new drivers for your IDE controller... If you are getting good throughput you should look into other stuff running on your machine that might be saturating your harddrive's bandwidth at critical moments causing problems with video playback.
Finally be sure you aren't mistaking the BYTE size of your disk cache for the BIT rate of your videos... 1 byte == 10 bits (8 bits data + 2 bits ECC) so if your video is asking for 10Mbps it requires a drive capable of delivering roughly 1.6mBps (note the capitalization, b is bits, B is bytes... and yes it's very confusing)
In any event I seriusly doubt that buying an expensive new hard disk is going to fix anything.
