I don't think it will too bad, but you would see significant gains from either the T7100 or the T7300 (the 7300 especially with the larger cache 4mb instead of 2). I would definitely upgrade to one of the T7xxx series over the T5s.
If you're gaming I agree with L&W, get the T7100-7500 with the 7300 being the best balance of price/performance IMO.
If you can swing it 2GB is also handy for Vista gaming.
And if you're looking for DELL be sure to check out the coupons out there to help reduce the price, makes a big difference, and one of the main reasons to buy a DELL IMO.
Check here for the latest;
Scroll down the list to this one;
Dell Inspiron $300 off $1399 Coupon Code (Dell Inspiron 1520 Notebook Computer (Core Duo T5450 1.66GHz/160GB/1.5GB))
Dell Inspiron 1520 Notebook Computer (Core Duo T5450 1.66GHz/160GB/1.5GB) Use code G01JG242730SDT to save $300 off this product (must configure price above $1,199.00 to get discount).Dell has a coupon code for $300 off Inspiron notebooks configured over $1399 plus free upgrade to 2GB memory and 160GB hard drive. Coupon Code Expires 7/26.