IPhone 4 3G Data Performance | Hacker News Reader

IPhone 4 3G Data Performance

daringfireball.net

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The speeds we're starting to see on next-gen mobile devices + networks are pretty impressive - more than can be used effectively without draining the battery in a hot second, at least. Now that we've got bandwidth figured out, it's time to tackle latency.

A coworker ran a speed test on his AT&T iPhone 4 in NE Portland at lunch and got about 1.4mbps down with a 150ms ping. I get about 3.9 - 4.3mbps down with an 80ms ping with my Nexus One (T-Mobile): http://j.mp/94sfpF

Both of these speeds are fantastic. The bandwidth question is highly network-dependent, and almost entirely moot once you're beyond the 800k mark -- especially with a low-latency ping, which is likely the biggest bottleneck when browsing the web.

We need device manufacturers and carriers to work closely, striving to reduce latency in mobile connections. For developers, it's critical to drive home the point of minimizing the number of HTTP requests. If you've got a minimum 200ms round-trip for each call and 98 items to load (NYT.com, tested a moment ago), it adds up quickly.

Amen to that. I wrote a test app which downloads a single image from the net. There is a progress bar so you can actually see how "quickly" the bytes come in. I kick off the request, and the majority of the time is spent waiting for the first byte. I was pretty surprised by this. All this time I was thinking it was the throughput that was slow; but no, the latency really is the killer here.

Bad latency makes for a terrible interactive terminal experience too. I remember SSH on my first gen iPhone was awful.

Improved latency is one of the major improvements that 4G (lte) has over 3G. Networks are already being rolled out, it won't take long until there is coverage in major cities.

The more you learn about the iPhone 4 the suckier the iPad first generation seems. You would have assumed that it was at least the iPhone 4 with a bigger screen, but they must have been really trying to hit a price point.

The WiFi iPad is great. I don't think it's real target audience is even likely to use it away from WiFi often.

It would be interesting to know what percentage of iPad sales are 3G vs. WiFi only.

Maybe so. The $499 starting price for the iPad is a very important part of its success. Another possibility is the iPad was in the pipeline before the iPhone 4 was designed and it was simply too late to re-design the antenna and integrate a new radio chipset. If you're working with a 12 month release cycle a delay of an additional 3 or 4 months is unacceptable. At some point they had to commit to shipping something

Remember, "it just works." The specifics, or the comparisons between the two, are not to be considered, I think. Consider the way that Apple would - particularly in epochs past - long, long lag behind comparably spec'd PCs for upgrades to the innards (for no particular reason). I don't mean to denigrate the buyers of iphones and ipads, I just don't think this kind of performance nuance is really cared about; the functionality is what's considered and so, latency or whatever else aside, things are comparable enough.

Something else I am not the first to notice: the "magic spot" problem doesn't affect Edge.

It really makes me wonder if there is an underlying software or firmware issue that is exacerbating the problem. The fact that upload isn't significantly impacted, nor Edge, suggests some sort of phone freakout that's not strictly dictated by the hardware to me.

The "magic spot" "problem" does not affect the Edge band for this particular user, in this particular location, on this particular day, in this particular phase of the moon.

Antenna design is black magic on the best of days. When you mix in all the variables at play across three million phone users around the country you get lots of irreproducible results.

What I find myself wondering is: Sure, closely coupling a big bag of saltwater (e.g. me) to the phone may [1] tend to reduce the antenna efficiency relative to leaving the phone alone on a table. But can I strap the iPhone into some sort of specially-designed case that's designed to increase the antenna efficiency?

[1] EDIT: This word used to be "will", but having just read Anandtech's fun analysis of this "problem", I am reminded that what giveth in one waveband taketh away in another: Anand improved his WiFi signal power under certain conditions by gripping the phone.

That is a very optimistic idea.

I wouldn't have mentioned the edge thing except that I've heard that sentiment repeated a lot, and I've asked other people for confirmation.

Can't say much about Edge, but I assume that the upload speeds are mostly unaffected because that is mostly transmitted data from the phone (though it would be interesting to see if the phone is cranking up the transmit power when the antenna is shorted)

Aside from being in control of it's power, why would transmitting behave any differently?

I live in an Edge-only area and I'm affected by the problem.

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