Can I use different gmail ids for Adwords and Adsense accounts?

At-least I have not come about such a mandatory requirement outlined by Google. You can use any GMAIL ID for AdWords and AdSense accounts, it doesn't matter if they are same or different.

You may use different gmail id for adsense account and AdWords account. But using same email id is more comfortable it reduce time consummation. And you can add more email id to your adsense account and log in with it directly

I believe one can use different gmail ids for Google Adwords account as well as Google Adsense accounts. I had a Google Adsense account for several years and later got my Google Adwords account using the same gmail id. However, I do know people who use different gmail ids for their Adsense and Adwords accounts. But, it becomes difficult to maintain and follow-up email notifications on two accounts. So, I would suggest you to use the same gmail id for both accounts. Another advantage of using same gmail id will be that when you apply for Google Adsense account, you would already have a good Google relationship with regards to Adwords account. Not that it matters a lot, but, a good thing to have as you need all things in your favour to get Adsense account approved.

Yes you can use different id for adwords and adsense. But I suggest you to use same id, it will save your time.