Test results related to iPhone OS 3.0 3G network speed problems

I've recently noticed poor 3G network speeds when using my iPhone, and wanted to conduct some tests to identify which of the following could be the potential culprit:

1. Could it be the new 3.0 version of the iPhone operating system?

2. Could it be the new 3GS model of the iPhone?

3. Could it be a problem with my 3G provider, Vodafone España?

UPDATE

The situation has not improved with the update to OS 3.1. Furthermore, OS 3.1 nuked my internet tethering, and so I'm now going to downgrade to OS 3.0. (I previously though tethering had been preserved, as it was still present in the user interface; however, when I actually tried to tether, it disappeared.)

SETUP

I've run these tests using a MacBook with OS X 10.6, and both iPhone 3G and 3GS models, running OS 3.0. (Also, I should note that both my iPhones are Apple official unlocked versions, purchased in Italy, i.e. they are not jailbroken.)

TESTS & RESULTS

A) MacBook tethering to 3G-connected iPhone (Speedtest.net)

For these tests, I had the MacBook tethered to the iPhone, and ran the tests at Speedtest.net using the Spanish "Elda" servers.

• MacBook tethered to iPhone 3G, 0.18 Mbps
• Macbook tethered to iPhone 3GS, 0.14 Mbps

For comparison, here are the results when: (a) untethered, and connected to the local Wifi, and (b) tethered to the 3G-network via a different phone than an iPhone.

• MacBook on local Wifi, 6.00 Mbps
• MacBook tethered to HTC phone, 2.5 Mbps.

B) iNetwork iPhone App Test

For these tests, I ran the iNetwork Speed Test application on the iPhones, comparing the results of being connected to the local Wifi, and connected via the 3G network.

• iPhone 3G: Wifi (2.3 Mbps), Vodafone 3G (0.12 Mbps)
• iPhone 3GS: Wifi (1.2 Mbps), Vodafone 3G (0.12 Mbps)

CONCLUSIONS

Based on the following tests, I conclude that the problem must be with the 3.0 version of the iPhone operating system.

• It's not a problem with the 3GS model of the iPhone, because the performance was similar on the iPhone 3G model.
• It doesn't seem to be a problem with Vodafone, as tethered performance using an HTC phone was fine.