EE Overview, page 17.
Memory Architecture:
Hybrid UMA
To correct the problems with UMA, each processor has a high speed, small capacity cache or working memory for exclusive use, and is connected to the large capacity shared memory through the high-speed memory.
By storing the data read from or written to memory in 4-qword units, the cache speeds up the second and succeeding access to the nearby adresses and decreases the frequency of access to the main memory.
Access to the main memory is made only when:
- the data attempted to be read is notin the cache (cache miss)
- the data written to the cache is not reflected in memory (dirty) and the cache space is required to be freed to access other addresses (cache out)
Data is transferred between the cache and main memory as burst access every 4-qword block (cache line) to improve the bus efficiency.
...
Image Decompression:
High-resolution texture data requiring a large amount of memory is stored in main memory in a compressed state, and is decompressed with a special decompression processor (IPU) when used. The decompressed texture data is returned to main memory temporarily and transferred to GS.
Geometry Data Unpack:
Modeling data is packed into an optimal width in data units, maintained in main memory and automatically unpacked by the VIF when sent to the geometry engine (VPU). As a result, the data size in main memory is reduced, and the load on the VPU can be reduced.
.
.
.
PS2:ssa on siis oma prosesorinsa (IPU) joka kompressoi/purkaa tekstuurit ja 3D mallit lennossa, muistintarve on siis pienempi kuin esim xboxissa, jossa vain tekstuuridata kompressoidaan.
PS2:ssa siis kompressoidaan koko bittivirta (Bitstream).
Lisäksi EE:n eri prosessoreilla, kuten VU yksiköillä on omat embedded data ja ohjelmamuistit (cache).
Xboxin 6.4 GB/s väylä on toteutettu Hyper Transport tekniikalla, jossa puolet väylästä on eräänlaista 'virtuaaliväylää', eli kikkailemalla aikaansaatu. Xboxissa voisikin sanoa olevan softapohjainen 6.4GB/s väylä
![Smile :) :)](https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f642.png)
Mitäs täällä onkaan sanottu aiemmin softapohjaisista ratkaisuista...
Slaisser, odotan sinun vastaustasi. Voisit laittaa vastaavaa selvitystä xboxista.