Most companies stick to the regular tax depreciation schedules, for computers 3 years is standard in most countries. You can deviate from this though if you can

Most companies stick to the regular tax depreciation schedules, for computers 3 years is standard in most countries. You can deviate from this though if you can justify it. And personally I wouldn't favor a new laptop over a pay raise, as the laptop will lose its value over time and is not yours to keep, while you can put a pay rise into your personal savings (and if you really want you can still buy a laptop from it).