The Samsung Galaxy S II Skyrocket and the new HTC Vivid are AT&T’s first 4G LTE smartphones, not to be confused with HSPA+ “4G” devices they’ve launched in the past. AT&T’s 4G LTE just went live back in September and so far they only have 5 markets currently with 4G LTE although 4 more are coming this weekend. We decided to give their relatively small 4G LTE footprint a run for its money and see how she performed. Details and speedtest results are available after the break.

Sadly we had to take a short road trip to even get access to a 4G LTE network as it’s currently only available in San Antonio, Dallas-Fort Worth, Houston, Atlanta and Chicago today and they’ll be adding Boston, Washington D.C., and a few others come tomorrow and Monday. Below are the results we found down here in Texas, both smartphones were next to each other and were ran one after another for a fair fight. This isn’t really Skyrocket vs Vivid — but more just an overall test of AT&T’s 4G LTE on two completely different devices.

The tests were performed later in the evening so might not have been fully loaded, if that matters to anyone. Our recent DROID Bionic review unit 4G LTE tested around 10-12 Mbps down in our tests, and T-Mobiles “4G” Amaze 4G received around 9-10 Mbps down on average for a small comparison. From initial tests AT&T 4G LTE was blistering fast, although not many users currently take advantage of it so that might also be taken into consideration. The HTC Vivid averaged well over 17 Mbps down and peaked at over 20 — impressive to say the least.

One thing to note on both the image above and below is the upload speeds we achieved with AT&T LTE. They are extremely fast and the Vivid (above) averaged around 9.4 Mbps Up, something Verizon nor T-Mobile even come close to. Our Bionic was getting around 2-3 Mbps upload speeds if it was lucky. Again, AT&T’s network is new and not under duress but these are some mighty fine results if I don’t say so myself. Next, we have the Samsung Galaxy S II Skyrocket. The tests were performed in the exact same location for as close to accurate results as possible and it held its own quite well too. The Skyrocket averaged around 16 Mbps download speeds while peaking around 19, and it also had exceptional upload speeds approaching 8.5-9 Mbps.

Now, obviously speedtest results don’t necessarily show us real world results for daily tasks such as web browsing and downloading games or applications but we experienced great speeds there too. Streaming Netflix movies or even 1080p video from YouTube was basically instant, and loading up web pages we saw a noticeable improvement over standard AT&T HSPA+ devices with load times. As usual, these results will vary from location, time, and user but so far we are pretty impressed with the small, but stable AT&T 4G LTE network.

4G LTE data plans you ask? They’re exactly the same as AT&T’s current 3G and “4G” HSPA+ plans. That means that you’re still limited to a maximum of 200MB, 2GB or 4GB of download and upload before getting charges for overages, unless you’re lucky enough to be grandfathered in on an unlimited plan or are paying that premium. Obviously being on the new 4G LTE these devices require a new LTE sim card, but did in fact work with older regular SIM cards under AT&T’s normal 3G and HSPA+ operating frequencies. These phones will come with new LTE sim cards so this shouldn’t be an issue but was worth mentioning.

We have handled and unboxed both the Samsung Skyrocket and the HTC Vivid this week (links at the top) and you can expect the usual full, in-depth review of both coming soon and maybe even this weekend if you’re lucky. Be sure and check back soon as the reviews will be live shortly.

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