MSI GeForce GTX 650 Power Edition OC 1GB Review @ RWLabs
 

The Nvidia GeForce GTX 650 was released alongside the GTX 660 last month, but unlike the GTX 660, which was available in volume to reviewers the GTX 650 was nowhere to be found. The reason being Nvidia actually told their board partners to not sample the GTX 650 until after the reviews for the GTX 660 went live. They stated this was an effort to ensure the GTX 660 didn’t lessen the impact of the GTX 650, but this did raise some red flags for us, because usually when a product isn’t sent out to reviewer there is a reason other than some of the thunder could be stolen by its older sibling.

http://www.rwlabs.com/article.php?id=718