COMO FUE PORTEADO THE CREW A PS4
PS4's memory subsystem has separate buses for CPU (20Gb/s) and GPU(176Gb/s)
Eurogamer has an interesting article on the process of porting Ubisoft racer The Crew from PC to PS4. In it, developers of the PS4 version speak in detail about the porting process. It's a fascinating read:
What caught my eye was the mention of two separate system buses, one for the GPU and one for the CPU. While the GPU bus has the full bandwidth of 176GB/s, the CPU one is 20Gb/s. Also, according to the devs, allocating data correctly between the CPU and GPU bus is extremely important in order to achieve good performance.
The PS4 operates a system where memory is allocated either to the CPU or GPU, using two separate memory buses.
"One's called the Onion, one's called the Garlic bus. Onion is mapped through the CPU caches... This allows the CPU to have good access to memory," explains Jenner.
"Garlic bypasses the CPU caches and has very high bandwidth suitable for graphics programming, which goes straight to the GPU. It's important to think about how you're allocating your memory based on what you're going to put in there."
"The first performance problem we had was not allocating memory correctly... So the Onion bus is very good for system stuff and can be accessed by the CPU. The Garlic is very good for rendering resources and can get a lot of data into the GPU," Jenner reveals.
We started off with a large codebase - there were about 12,000 source files. And we started with a 64-bit Windows version of the engine using D3D11," says Reflections' expert programmer (yes, that is an actual job title), Dr. Chris Jenner. [...]
With the basic porting complete, the Ubisoft Reflections team is now ramping up its staff in order to complete the PS4 game ready for the Q1 2014 release, but the core engineering effort in moving The Crew across to PlayStation 4 was accomplished in six months with a team of just two to three people working on it. Overall, Reflections felt that the process of porting over the PC codebase was fairly simple and straightforward.
"The PS4's GPU is very programmable. There's a lot of power in there that we're just not using yet. So what we want to do are some PS4-specific things for our rendering but within reason - it's a cross-platform game so we can't do too much that's PS4-specific," he reveals.
"There are two things we want to look into: asynchronous compute where we can actually run compute jobs in parallel... We [also] have low-level access to the fragment-processing hardware which allows us to do some quite interesting things with anti-aliasing and a few other effects."
http://www.eurogamer.net/articles/digit ... w-was-ported-to-playstation-4
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Lo más interesante:
"The Crew , a PlayStation 4, se llevó a cabo en seis meses con un equipo de sólo dos o tres personas . En general , Reflections consideraron que el proceso de portar el código base de PC era bastante simple y directo".
"La GPU de PS4 es muy programable . Hay una gran cantidad de energía allí que simplemente no estamos usando todavía . Así que queremos hacer algunas cosas en PS4 específicas para nuestra representación, pero dentro de lo razonable - es un juego multiplataforma, así que no podemos hacer demasiado en PS4 especificamente".
Saludos.