iPad: Bad 3G antenna or AT&T throttling upload speed?

[Macuser1628]

Hello, I ran some 3G benchmarks on my iPad and iPhone 4 and consistently saw that the iPhone got upload speeds approximately 10X better than my iPad 3G. With the exception of the topmost test (12:58), these tests were performed in an alternating fashion, such that first Id run an iPhone test, then an iPad test. These tests were performed at my home, which has a cell tower on my roof.

The topmost benchmark i started both tests simultaneously to see if there was any competition for bandwidth, but it appears minimal.

So, is AT&T throttling 3G service on the iPad or is the antenna/chipset on the iPhone ~10X better on upload speeds?
Results are in kiloBytes/sec.

 

[Night Spring]

No idea, but how would AT&T selectively regulate upload speed based on device? Does any technology exist that would allow them to do that?

 

[Macuser1628]

No idea, but how would AT&T selectively regulate upload speed based on device? Does any technology exist that would allow them to do that?

Maybe it's not the device itself but rather the service plan? I have the 2GB plan on the iPad so perhaps they can detect what kind of service is doing the upload/download and throttle it appropriately?

Maybe it's not the device itself but rather the service plan? I have the 2GB plan on the iPad so perhaps they can detect what kind of service is doing the upload/download and throttle it appropriately?

If I had the guts to do it I would temporarily put my iPhone 4 sim in my iPad and benchmark that. But I'm too afraid that something will break.

 

[Night Spring]

If I had the guts to do it I would temporarily put my iPhone 4 sim in my iPad and benchmark that. But I'm too afraid that something will break.

Good idea. I've heard people doing this, but usually they are trying to get away with having just one data plan for both devices. I haven't seen any reports of any ill effects, but again, it's not a topic I'm very interested in, so I haven't followed them closely. You could check in the iPhone/iPad hacks forums to see if anyone's reported problems with swapping sims.

 

[Macuser1628]

Good idea. I've heard people doing this, but usually they are trying to get away with having just one data plan for both devices. I haven't seen any reports of any ill effects, but again, it's not a topic I'm very interested in, so I haven't followed them closely. You could check in the iPhone/iPad hacks forums to see if anyone's reported problems with swapping sims.

I tried it. It's very easy to do actually. Just place the iPhone 4 sim in the iPad, power it up and change the APN settings to phone instead of broadband.

There was no change in download/upload speed, so the only safe assumption is that the iPad's 3G antenna/chipset is nowhere near as good as the iPhone 4 antenna/chipset. That would be for both upload and download speeds.

I ran the same benchmarks for wifi and the iPad's wifi antenna/chipset gets better download speed about 1.8MBytes/sec on iPad compared to 1.3MBytes on the iPhone 4.

 

[Gav2k]

The 3G chips inside the iPad are the same as the 3GS not the iphone4. You'll always see slower upload speeds. If you were testing along side a 3GS then you would get comparable results

 

[Macuser1628]

Download 3G speed is ~2X better on an iPhone 4 than on the iPad 3G. Upload speed is ~10X better on an iPhone 4 than on an iPad 3G.
I get an average of download/upload speeds ~ 2.5Mbps/1Mbps for an iPhone 4, compared to download/upload speeds of ~1.5Mbps/0.20Mbps for my iPad 3G.

Wifi speed is better on the iPad however.

I've been corrected and told that it's the 3G chipset in the iPad and not the antenna. Nevertheless....

 

[Macuser1628]

The 3G chips inside the iPad are the same as the 3GS not the iphone4. You'll always see slower upload speeds. If you were testing along side a 3GS then you would get comparable results

Yes, but ~ 10X slower? Isn't that a bit much?

 

[TheBritishBloke]

Well thats a pile of bull. I get full 5 bar signal on my iPad even where I get no 3G signal on my iphone 4.

But the iPhone 4 does have HSUPA which is fasted than the iPad at uploading.

 

[Macuser1628]

Well thats a pile of bull. I get full 5 bar signal on my iPad even where I get no 3G signal on my iphone 4.

But the iPhone 4 does have HSUPA which is fasted than the iPad at uploading.

Is HSUPA also responsible for the 2X better performance for download speed as well?

Yes but keep in mind that:

1) I'm talking data transfer rates not ability to hold signal. The iPhone 4 sometimes has an issue with signal holding (or so I've been told )

2) the way bars are displayed on the iPad has yet to be "corrected" the way it was on iOS 4.0.1 (or did 3.2.1 also update the bar display on the iPad 3G to the new calculations?)

3) I love my iPad

 

[kevink2]

Plus towers can apparently be misconfigured. I get 58kb/s upload speed on my iPad at work, and I can get over 1mb/sec upload on my iPhone 4 at the same time in the same place. Go home, and the iPad jumps to 200kb/sec upload.