dahuman on 09 June 2012
gumby_trucker said:
so the theoretical maximum transfer rate for USB2.0 is 60 MB/s (480 Mb/s) but the actual maximum transfer rate is closer to half that number:
"the full real-life maximum throughput of USB 2.0 is approximately 32 MB/s" according to Tom's Hardware.
For comparison the Xbox 360s optical drive had a transfer rate of half that number at around 15.8 MB/s and the PS3 even less than that. Since by default games are read from the Optical drive, that is the transfer rate we have to beat, and we must do it consistently.
Blu Ray 1x read speed is 36 Mbit/sec but no commercial drive is any slower than 2x because you need at least 54 Mbit/sec to play movies. This means that in order to have an optical drive that is faster than USB 2.0 Nintendo would have to go with an 8x BluRay or better. Having an 8x BluRay drive would seem to be overkill as it would have transfer speeds 2-2.5 times faster than the fastest console this gen, the X360. That leaves us with 4x or 6x drives.
In 2006 Sony went with the cheapest drive possible which is 2x (=72 Mbit/sec) because they needed to keep costs low. As a result they created a severe bottle-neck in data access (even slower than the 360 DVD drive) and this has hampered developers all through the generation. Nintendo would be stupid to repeat this mistake, especially since prices have gone down a lot since 2006.
For now I am assuming Nintendo will go with the cheaper option, i.e. 4x Bluray which means 144 Mbit/sec for continuous reads. This puts Wii U slightly above the 360, which had a 12x DVD drive at 132 Mbit/sec maximum read speed. Remember that Wii U has WAY more RAM than the PS3 or 360, therefor even if assets are in higher resolution I don't think it justifies going with a faster drive than 4x Bluray. If the system can stream data not only to RAM but also to the onbaord Flash memory than this is even more true.
Now hard drives for the 360 and PS3 were probably faster than this, but still, any decent USB 2.0 drive today manages actual transfer rates of 22-26 MByte/sec = 176-208 Mbit/sec. This is something I can attest to, having recently purchased such a drive and doing the comparisons myself. Therefor as long as the drive doesn't drop below 18 Mbyte/sec (=144 Mbit/sec) during continuous transfers, it shouldn't make a difference to the software in comparison to 4x BluRay as far as data being delivered. Even if Nintendo does decide to go with 6x Bluray (216 Mb/2 or 27 MB/s), many top of the line USB 2.0 drives would still be able to exceed the optical drive's transfer rate.
There are crappy USB 2.0 drives in the market that don't do 18 Mbyte/sec continuous, but as long as customers know to avoid them, we should be fine. Therefor Nintendo would be smart to publish a "consumer guideline" document on what drives are supported so customers don't end up buying a cheap and slow drive and missing out, and also in order to ensure developers that software installation is a non-issue.
So, bottom line what this means is there is no reason to believe games won't load faster on Wii U's optical drive than they do on X360, and certainly much faster than on PS3 based on the hardware alone. If you take into account further optimization, which you will definitely see in Nintendo games, I believe loading from the optical drive will be noticably faster on Wii U than on X360. The downside is that there will probably be less of a gain to installing games on a HDD in comparison to PS360, but even then, there should be some improvement over streaming from the disc.
Finally, if instead of installing to HDD you decide to go with a large SD card as your internal storage then all this is completely irrelevant since speeds and transfer rates are much higher there anyway. (SDHC goes up to 32 GB, but 64 GB cards have also been seen. The newer standard, SDXC, goes up tp 4 TB).
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you forgot to mention the difference in seek time, optical drives have terrible seek times in general so if multiple assests are being loaded, HDD would be faster anyways. If you are crazy enough to use SSD on USB2, which I don't recommend, it'd be even faster. SD Cards also have faster seek times as well, SDHC Class 10 only does about 10MB+/- per second though, not the most ideal for data streaming heh, but very good seek and burst buffer rates.
