Sorry to resurface an old thread, but I thought this might be useful to some people.
I9100T phones seem to need I9100T modem firmware to ensure usable data speeds. They can be flashed with ordinary I9100 ROM and kernels, but reflash with I9100T modem firmware afterwards.
there is more of a difference between the I9100T and the standard I9100 than just the SARS value. Here is why I think so.
I have a I9100T purchased from Telstra in Australia - and I use it on the Optus network. When I received the phone it had modem firmware DVKF2 and kernel DVKF4.
The first thing I did after getting the phone was to flash it to Cognition v1.31 (XXKG3). After a few days I realised I was getting terrible 3G speeds – like 900ms pings and 30kbps up/down. So I flashed the modem to DUKF2 (I couldn’t find a DVKF2). Things seemed to perform much better but my phone seemed to jump from 3G to H intermittently and while speeds were fast, there was large “gaps” as it re-negotiated from 3G to H and vise versa.
So with the DUKF2 modem firmware in place I went searching for solutions and found the *#301279# code (which lets me control 3G, H and H+ modes). Just to repeat, I am using the Optus network, so there is no possibility of me reaching H+ speeds. My results are from the SpeedTest app. Here is what I found:
- 3G only: Speeds were only marginally better than flashing the modem with a non-I9100T firmware. 250ms pings 300kbps down / 200kbps up.
- 3G and H: The odd part is that in this mode the phone never jumped up to H. It stayed on 3G all the time. Weird. Anyway, I was getting 180ms pings and around 2 Mbps down / 300 kbps down. Now, things seemed to be more stable. After the initial ramp-up in speed, the chart would roughly resemble a table top as if I was hitting a speed limit.
- 3G, H and H+: This enabled the switching up to H mode. The speeds were the best here as I could get anywhere between 2-4 Mbps down and 300-500 kbps up. Pings around 100-200ms. The problem was the speed was “erratic” The charts were nowhere near as consistent as being in 3G and H mode (where only 3G was operating). This is because the phone seemed to negotiate between 3G and H and that would cause gaps. Sometimes it did this 2-3 times in the one test – and the test only goes for something like 10-15 seconds!
Just to make it clear, I tried all of these modes under a few different modem firmwares such as XXKF2/3 and XXKG3 that were made for the I9100 and I had terrible speeds regardless. It was not until I flashed I9100T modem firmwares did the speed improve.
What do you guys think? I have read that others in similar situations (Telstra phone I9100T on Voda or Optus networks having poor speeds). Or could it just be my phone and I should return it?