Unfortunately, you've not told us anything about the computer.. Operating system, processor speed, amount of RAM installed, and most importantly, what type of graphics card you have installed. Plus since you didn't tell us, I'll only guess "really slow" refers to playing of games through the laptop to the TV..???
Either way, since a good graphics card is key to good performance on any monitor, especially if you have your TV set to a high resolution, laptops aren't the best tools for such purposes.. Generally, laptops have underpowered, integrated graphics cards.. Is that your situation? If so, then it won't matter which type of cable you use.. The video card will stay the same. Tried adding more overall RAM?
Hope this helps.
I have my HP Pavilion laptop connected to my HDTV via an S-cable. The display looks good, but it's just really, really slow. The performance seems to be dramatically slowed down. Would a different type of cable change this, or is this just a normal effect from using an external monitor?