Comments on: Which is faster: Blu-Ray or DVD?

By: Darrin

Darrin — Wed, 30 May 2007 17:08:36 +0000

I think Bonnie++ sounds like a good benchmarking tool to use.

I will need to get Linux setup on my PS3 to run.

By: Sporty

Sporty — Wed, 30 May 2007 13:04:53 +0000

I don’t have linux installed on my PS3 yet.

But anyone that does can do this test for Darrin.

‘hdparm -tT /dev/cdrom’

With a BD in the drive. Should give the transfer rates.

But this isn’t a perfect test. just the best we can do. Should do 3 tests and post the average.

By: Darrin

Darrin — Wed, 30 May 2007 11:51:01 +0000

I’ve read the specs and I know about the hard drive.

What I want to see is actual benchmarks. Not theory based on abstract numbers, but actual test data.

Seriously, I wanted to run this test before posting about it, but I’ve hit some hold ups (not tech related: I bought a new HDD by mail that I never received and was likely stolen) and was hoping someone else might have some better ideas or help run such a test while it’s still relevant.

By: Segitz

Segitz — Wed, 30 May 2007 08:14:09 +0000

Theoretically, the 360s DVD ROM is faster. But only in theory. This DVD ROM is a max 12x (15.9MB/s). Interestingly, I’ve just searched for the real specs for this drive (a CAV drive has a min and a max speed, and mostly are slower while reading dual layered discs).

It is said (also on B3D forums) that the 360s DVD drive can read dual layered DVDs only with a max speed of 8x (~10.5MB/s), which is only a LITTLE bit faster than the PS3s constant 9MB/s (2x at 4.5MB/s). So theorizing this further, 360 games can only read faster than the PS3 in less than ~50% of its discs.

This takes into consideration a) perfect drives b) perfect conditions and c) perfect discs and that the drives reach their theoretical maximum read speed.

Difference can also be made by looking at the density (~7-8GB against 50GB) of the discs. Like the Bethesda guys said, they use more space to better loadtimes (i.e. lessen the seektimes of the optical drive to up the read speed, as a constant read is much faster than constant seeking). Also, they can put the data on the BD ROM anywhere, it reads at the same speed. The DVD needs to be padded to achieve full reading speed. And with titles that are close to the maximum capacity, this aint possible.

Also, all PS3s have a harddrive, which can be used for streaming data. The 360 can be equipped with one, but it is not standard, which makes devs consider it, so they cant take full advantage of a harddrive.

Sorry, I need to leave now… going shopping for new goods at a “special” supermarket (cash and carry it is called in britain afaik).

By: bobeotm

bobeotm — Wed, 30 May 2007 06:33:33 +0000

Part of what makes the speed discrepancy a non-issue is because of the PS3′s standard harddrive, games can cache without having to constantly stream and find items on the disk. A game can simply temporarily write frequently used assets to the harddrive and use it to supplement that which is retreived from the disk.

The speed of the drive isn’t as much of an issue, as making sure the space is used intelligently. If games would be compess to dvd9 size when they are small enough to, while still being on blu-ray, would provide an advantage. Because it could mean that an entire 4gb game could occupy a narrow band on the disk, causing there to be less of a demand on the lazer traveling back and forth for to retreive disk info.