It's still only 1.3Ghz, you don't combine core speeds. Think of multicore processors as a highway. More cores(high way lanes), allow more data(traffic), to be processed simultaniously. It doesn't double your processing speed because adding another lane to a highway doesn't increase the speed limit.
Your CPU is the Intel® Core™2 Duo Processor SU7300. It's frequency is in fact 1.3GHz which isn't that fast really by todays standards, however it is a dual core processor and it should perform fine if you're browsing the web or editing word documents etc. I wouldn't expect too much out of it for any particularly intensive applications though.