updated 02:00 pm EDT, Wed May 4, 2011
Galaxy Tab Wi-Fi has older components than 3G
The Wi-Fi-only version of the 7-inch Samsung Galaxy Tab uses lower-spec components than the 3G version, beyond just the radio. As confirmed the official page, the Wi-Fi tablet uses a 1GHz A8 Cortex CPU paired with an older PowerVR SGX530 graphics core. The 3G version of the tablet has a 1GHz Cortex A8 as well, but it's a newer generation C110 version, the Hummingbird, along with a newer SGX540 for video.
The resulting slow performance of the Wi-Fi tablet is well documented by users on the XDA Developers forum. They and others have lashed out at Samsung for giving users the low speed, particularly given the late timing. Galaxy Tabs with 3G were reaching stores as early as September 2010, but the Wi-Fi version isn't reaching customers until well after Apple and others had eclipsed both Samsung tablets in performance.
Other features have also shown some degradation, as the Wi-Fi tablet gets Bluetooth 2.1 rather than Bluetooth 3.0, again according to the product page. [via CarryPad]