My hardware can't run the code I need for my research I have started doing a project and I promised to report my results every week to my professor. At the beginning, he told me you should have a reasonably good laptop. 
I thought my laptop could support the project.

Yesterday,  I realized that my laptop has a 2G graphic card and the project needs a laptop with the at least 3G graphic card. I have written the code but my laptop can't run the code to see the results.

What should I tell my professor? 
If I buy a new laptop it will take about 1-2 weeks, however my financial support from my family is poor.
It should really be the responsibility of your professor to secure the required equipment to successfully complete your project; it's not quite right on his part to demand that you pay for any part out of your own pocket. Typically, a laptop is cheap relative to the professor's grant whereas it is unrealistic to expect a student to pay 1k to 2k. After all, the work you do is probably for a project that your advisor has funding for, and it's as much to his benefit as yours to successfully complete it. If he requests you to pay, it seems like he's talking advantage of his students.