What's most important for recording?

I currently have a base model mid 2011 Macbook Pro 13 inch. I just recently purchased a Blackmagic Intensity Exterem for recording xbox gameplay and streaming. I was wondering if buying a better hard drive or 8gb of ram would help with recording or streaming, since I currently get choppy video with audio that isn't synced up while doing either. Someone with my same computer (except for 8gb of ram) has been uploading videos on youtube and the video looks clean and is 720p, but he hasn't streamed with it. Can 8gb of ram balance everything out, or should I look into upgrading to an iMac for what i'm trying to do? ty

I can't give you a direct answer but here's something I've noticed from using the older Intensity Pro card in my Mac Pro w 4 GB of ram. I haven't done game play captures but have done other HD and SD stuff.

Most of the time the captures are pretty good with my setup. The one time I consistently got out of synch audio was when I put a new hard drive in for more capture space. I got a good deal on it but did not notice it was a 5400 rpm drive. When I switched back to a 7200 rpm drive the problem went away.

Alright yeah that makes sense. I did the disc speed test and my marks for what I could handle
pretty low. Still don't know if that'll solve the streaming problem but I'll look into rpm for the recording problem...maybe SSD

I just thought of something as I read your last post. Where will you be saving the files. I seem to remember with the card that I have it suggest the video not be saved to the same drive as the boot disk, I'll try to find a more definitive answer when I have a moment.

My Blackmagic allows me to save to the drive on my laptop. I have an external thats 7200rpm but it's read only from my mac and full, until I can find a place to store all my files I can't reformat it. That'll solve the recording problem, least for now. As far as my stream goes I can record at 720p 60fps and then downgrade it to 640x360 for now, but I get about 1-2 seconds of audio lag...anyone know if this is because my mac is working so hard to downgrade the resolution?

Click here to watch my test recording

It's not so much whether the software allows saving to the boot drive that is the issue as much as there being a lot going on on the drive at the same time. In addition to the demand for drive time created by the video capture the OS is also saving virtual memory files to the drive from time to time. I am not sure that is the issue but it is something to think about.

I have not tried to do a resolution downgrade "on the fly" as you are doing. It might be worth doing a short test clip without the downgrade to see I have not done a lot with the kind of streaming you are shooting for so this is mainly guesswork based on a few other things I have done.

You might want to post your question at VideoHelp.com Forum. They have a section specifically devoted to Mac issues as well as one devoted to issues regarding streaming. Some of the discussions go over my head and into the technical weeds sometimes but there are some very knowledgeable folks there.