Todays average PC vram?

How to know if mygame will run on most pc? We know how much vram ipad had but What about average PC vram nowaday? 256mb or 512 mb minimum? Maybe there's a statistic about this topic or I have to deduce from the current lowest onboard graphic vram. Everyone please verify this...

1gb vram is on most discrete video cards, with many now 2 to 4gb. iGPU from Intel such as HD4000 uses system ram as vram so its not an issue.

1gb+ is most popular, 512mb is probably a good limit goal (~13%), and about ~5% have less than 512mb.

http://store.steampowered.com/hwsurvey

Some low-end laptops (and possibly PCs?) do not have any VRAM, and share system memory like mobile phones do. Also Steam stats are likely biased towards high-end gaming systems, and it still says about 5% of users have only 256mb VRAM, so I'd consider that the limit if you want your game to run effectively universally.

Integrated graphics from Intel (HD4000 etc) or AMD use system ram for vram so its actually not an issue as most of those come with at least 4GB of system ram for awhile now.

thank for the reply guys