Digital Foundry Article Technical Discussion Archive [2013]

If you check the gta5 thread you will find it really differs from person to person, many varieties of hardware I guess. But on the old fat with 60 GB it seems the worst. While others didn't notice.

Is there any dd 360 version announced, that would be very bad.

 

Couldn't they just install the game to a fast usb thumb drive to solve pop in issue, or does the 360 no longer allow that? I figure if you eliminate the seeks (thumb drive on 360, ssd on ps3) then maybe that would resolve the pop in issue on both machines.

 

It would be about as bad as installing both disks, is.

Perception differs from person to person also.

 

Rockstar clearly has put all effort and testing for it to be played HDD+disc.

Its just the BD-ROM dump thats on PSN that performs slightly better than a manual install from two separate discs on 360 because the data is slightly closer. Could it be fixed to perform better from HDD only or not? Who knows

There were 360 games that performed worse when installed like Halo 3 because the data was so organized to DVD read performance

 

GTA V must really be optimized, as on my PS3 the digital download version of The Last of Us performed much better compared to the BD version.

 

With having to account for live streaming and recording, and background downloads, next gen HDD streaming bandwidth should see a drop compared to this gen I guess. Do we know what kind of HDD's they're using? 7200rpm?

 

Of old or new speeds? I'm just looking at current 2.5" 500GB drives, and assume that the file system / encryption overhead wil be minimal this time, especially with both parties realizing that digital downloads and large memory pools need to make the most of the HDD

 

What? We have 8 year old hardware now with specs that fit that for streaming. Compare that with next generation and it should be just fine.

Background downloads will be buffered as will recordings and should be very easy to write to disc without hampering the streaming by anything significantly.

 

New speeds. Doesn't look like there's any known specs on the HDD aside from capacity, but if it's 100mb/s as you suggest then it's probably adequate, with a 1 gb or so buffer in ram.

@tkf, yes streaming on our ancient machines is doable of course. Just wondered if a purported 3-4x jump in HDD speed would be adequate. I think so, if we account for buffer in ram. Haven't kept up with HDD technology very much in the last few years.

 

Where are these 100mb/s hdd speeds coming from? Seems a bit high to me...bearing in mind hdd speeds haven't changed much in years, I can't see why such high speeds are expected all of a sudden. Also the highest speeds are only achieved during sequential data access. I can't see why assets in an installed game would be sequential. Eg Texture A is on one part of the platter, texture B is somewhere else. As the heads physically move you have a seek time penalty. This would result in getting substantially less than max throughput...Furthermore the constant writing of the video to hdd is going to further disrupt the sequential pattern.

 

The 100mb/s is on the low side for typical 3.5" drives and the same for the mobile drives too. The advancement comes from bit density on the tracks, not from mechanical speed. The rotations such as 7200rpm vs 5400rpm typically only make a difference in latency. My green drives I use on my multimedia file server are 4 years old at 2tb and have read rates in excess of 100mb/s. The higher density 4tb drives with 4 platers are real speedsters.

 

Just google tests for current drives ...

 

I've got 4 Seagate Barracuda 3TB drives running in a QNAP412. This is just running as a DLNA server and nothing else. They use 3x1TB platters rather than 5x600GB platters. They max out at ~190MB/s for R/W.

 

But that latency is potentially the largest influence on random read speed depending on the size of the files read. Which is why loading game data and streaming from a 5400 RPM drive compared to a 7200 RPM drive is significantly worse than the sequential transfer speeds would indicate. And why SSD's are sometimes quite dramatically faster and sometimes not quite as dramatically faster for level loading.

Regards,
SB

 

Could the 8GB of flash cache on the XB1 be of any use as a HDD cache? Or is it too small and/or wear-prone to be used that way?

I was thinking that maybe the game could load the flash up at run-time or install-time with 5-6 GB of data that is potentially too "thrashy" to be read off a drive, or perhaps is just extra time-sensitive in nature, while leaving the stuff that can be read more sequentially on the HDD. I'm not sure whether it's possible to determine ahead of time what should profitably be put where. Maybe some sort of profiling done before the game ships?

Obviously, if it's stuff you're gonna need all the time, and it absolutely, positively needs to be there on time, you'll just pre-position it in RAM. Since there's just as much RAM as flash in the XB1, I sometimes have a hard time visualizing potential uses for the flash. Something like 32GB of flash would seemingly be a better "fit" as a buffer between memory and drive. Surely there must be some way to derive a performance benefit from that flash, however.

I guess you could just treat the flash, conceptually, as a small additional drive, onto which you "install" part of the game, while the bulk of the install goes onto the HDD as usual. That would allow you to occasionally be sucking data into RAM from "two drives at once", much like GTA V allegedly does via both the 360's HDD and its optical drive. But there again, you'd have to worry about that "install" happening too many times, which could wear out the flash.

 

Its used to assist in OS switching. Allowing for faster Snapping to the OS and improved OS functionality. Not for games.

I was looking at eMMC4.5 transfer rates and it varies slightly depending on brand. But if you are looking at the 8GB size available you are seeing 40-60MB/s read rates on mlc. emmc controller readwrite speeds scale according to the memory size, and 8gb being on the lower end sees lower end performance.

 

Regarding the article

"Streaming issues hit PSN digital version of Grand Theft Auto 5 " on DF.

I bought the digital downloadable version on PSN and I have a "phat" PS3 with a 320Gb 7200rpm HD. I have played the game up to the dog scene. So far I don't have any of the texture streaming problem that is shown here.
I will try play the game some more now over the weekend and report back if some of the streaming problems occur later on.

/ Ken

 

I think the issues are entirely related to how fast your hard drive is. A launch 60GB drive is basically a worst case scenario for the problem (and considering how few PS3s were sold in the period it's a bit disingenuous to use that to represent a typical user's experience). The newer and faster your hard drive is the less of an issue it should be.

 

That is true, but I believe COD4 at least, implemented loading levels as a big 'chunk' / "zip file", so that it wasn't affected by drive latency.
So they can implement that, although it will be at the cost of hdd memory.

 

Additionally, it has been discussed here that the wear and tear caused by constantly using the flash memory as a cache could reduce it's lifespan considerably and a memory of this type could last only 3 years if that was to happen which could be a disaster, taking into account the console stores all the OSs there.