More iPad Battery Notes: 25-Hour Hotspot Life, 2-Amp Current Draw from Discharged State

[Rocketman]

Rocketman, I didn't know you were one of the supporters of the fabled xMac. I previously stated that under SJ this would NEVER happen...

But if Cook is as soft as he was for dividends, you may actually have your dream come true

Bow and pray.

 

[BiggAW]

These statements are somewhat contradictory - if *both* USB and WiFi are slow, perhaps the memory chips *are* the bottleneck.

Flash can be painfully slow, especially if there's only one "bank" of flash memory.

Fast SSDs, thumbdrives, SD cards, ... use multiple banks of flash memory in a RAID-0 like configuration to read/write in multiple parallel streams.

USB isn't that slow, but neither technology has a lot of bandwidth for data-intensive uses like that.

I don't have an issue with the speed, the reliability is my issue. The first time I got the iPhone was a disaster, it took several syncs to get all of my 6,000+ songs on my 64GB iPhone 4S.

 

[AidenShaw]

USB isn't that slow, but neither technology has a lot of bandwidth for data-intensive uses like that.

I don't have an issue with the speed, the reliability is my issue. The first time I got the iPhone was a disaster, it took several syncs to get all of my 6,000+ songs on my 64GB iPhone 4S.

Reliability of USB is a problem? Outside of tripping on the cable, I've never had any failures to blame on USB.

 

[BiggAW]

Reliability of USB is a problem? Outside of tripping on the cable, I've never had any failures to blame on USB.

Should have been more clear. It's not a hardware issue, it's how Apple implemented it in software. I have no hardware issues with USB. Knock on wood, I haven't had issues since.

 

[Cubytus]

These statements are somewhat contradictory - if *both* USB and WiFi are slow, perhaps the memory chips *are* the bottleneck.

Flash can be painfully slow, especially if there's only one "bank" of flash memory.

Fast SSDs, thumbdrives, SD cards, ... use multiple banks of flash memory in a RAID-0 like configuration to read/write in multiple parallel streams.

None of these examples use USB as an interface. WiFi can't expect to go above 48MBps real-world (280Mbps if you're lucky enough to find a 802.11n Tomato-compatible router). This is a far cry from USB's theoretical 480Mbps. As BiggAW puts it:

USB isn't that slow, but neither technology has a lot of bandwidth for data-intensive uses like that.

Especially not considering the large overhead required.

I don't think banks of flash memory are to blame. USB keys typically use only one memory chip, yet they "feel" faster to load with data than i-devices.

Even if banks were to blame, them plus USB or wifi overhead would lead to a painful experience.

 

[AidenShaw]

None of these examples use USB as an interface. WiFi can't expect to go above 48MBps real-world (280Mbps if you're lucky enough to find a 802.11n Tomato-compatible router). This is a far cry from USB's theoretical 480Mbps. As BiggAW puts it:
Especially not considering the large overhead required.

I don't think banks of flash memory are to blame. USB keys typically use only one memory chip, yet they "feel" faster to load with data than i-devices.

Even if banks were to blame, them plus USB or wifi overhead would lead to a painful experience.

What are the data rates achievable with Idevices?

Cheap USB thumbdrives are almost always single bank devices, but the higher performance thumbdrives (e.g. Corsair Voyager in larger capacities) are multi-bank.

Attached are the performance figures for a Voyager USB 3.0 drive - note that the write speeds for the 8GB/16GB drives are easily handled by USB 2.0, and the 32GB drive is maybe 10% faster than USB 2.0.

I think that it's looking more and more like the bottleneck is the Idevice, and not the connection.

 

[Cubytus]

Sorry to say, but I don't take USB 3.0 as a benchmark. Even in non-Apple computers, it is still pretty rare: I had computers from 2010 and 2011 to repair for friends, and none of them had USB 3.0, yet cost upwards of $900 each, which is high range as far as PCs are concerned.

From a usability concern, having a high performance USB drive is useless when it's under 4GB. The performance difference isn't worth the price difference.