Micron Starts Sampling GDDR5X Memory to Customers
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Kaarme
Can't the manufacturers just use it for their profit by further cutting the memory bus width since less can give the same result if its faster? They seem to like doing that of late.
Robbo9999
Fox2232
GDDR5 has 170 pins per package, GDDR5X has 190 pins per package. Their prognosis for early chips is 25% higher throughput per pin.
Signaling pin count went up from 67 to 68 which does not increase complexity of PCB.
Means one chip should deliver 1.25 * 190/170 = 1.397 ~ 40% higher transfer rate than GDDR5 standard package.
Or does that mean 1.25 * 68/67 = 1.269 ~ 27% higher transfer rate than GDDR5 standard package?
Number of pins goes apparently up by ~12%. Chip is accessible in x32 and x16 mode (faster and slower). But signaling pin count stays practically same, so PCB complexity stays same per memory chip.
x16 mode is to allow communication through lower amount of traces (lower speed), but to allow another set of traces to connect another chip ("doubling" capacity per traces used).
- In reality one GDDR5X is connected in standard way and another is connected behind it (easily on other side of PCB).
I can see potential for next GTX970. While memory controller may be 384bit, 2 chips will share traces for higher capacity. I'll keep an eye on memory layout from now on when I check GDDR5X graphics cards.
- this sharing is done in following way:
- > GDDR5X uses 4 data and 4 error correction channels, has command and address bus
- > in x16 mode 1st memory chip gets 2 out of 4 data and 2 out of 4 error correction channels. 2nd chip gets another 2 of each. 1st chip gets command and address bus and relays required information to 2nd chip if appropriate (extra latency?).
Edit: Actually little correction for underlined text:
It seems that command and address bus is directly shared, so there is another logic behind which tells chips if command is for them (maybe both read required address and check if it is in their scope). (still extra latency)
Xionor
Well this suddenly makes the recent Geforce X80 leaks very plausible.
(Lurker for many years, first post ever.)
Robbo9999
Robbo9999
poornaprakash
There are rumors about Nvidia Pascal being an improved Maxwell core with HPC capabilities, which still lacks crucial Dx12 Async Compute feature.
"According to our sources, next GPU micro architecture Pascal from NVIDIA will be in trouble if it will have to heavly use Asynchronous Compute code in video games.
Broadly speaking, Pascal will be an improved version of Maxwell, especially about FP64 performances, but not about Asyncronous Compute performances. NVIDIA will bet on raw power, instead of Asynchronous Compute abilities. This means that Pascal cards will be highly dependent on driver optimizations and games developers kindness. So, GamesWorks optimizations will play a fundamental role in company strategy. Is it for this reason that NVIDIA has made publicly available some GamesWorks codes?"
Source:
http://www.bitsandchips.it/52-english-news/6785-rumor-pascal-in-trouble-with-asyncronous-compute-code
Fox2232
norton
Noisiv
Stormyandcold
Brute force approach it is then.
Logically, Nvidia only has to be 5-10% faster than AMD to negate the benefits of AC for a tie. We can also expect a nice boost to dx11.
Fox2232
PrMinisterGR
If sampling happens now, whatever comes out needs at least 4-5 months until it could go to actual mass production. There is also the question of the memory controller design with no memory samples.
Fox2232
Not necessarily, you do not even need to know final pin layout on memory chip.
All you need is to know final specification for:
- how many signaling pins it uses
- way signals are processed
- and frequency it operates at (+timing)
Same way AMD built fiji and at time HBM had early samples, AMD had early fijis and they had it connected on early interposer.
Question of availability is valid, but GDDR5X in not revolution. It is not complex thing to make. Volume production for this is as big question of time as asking factory in china to start producing 130nm ASIC consisting of 2 million transistors. They'll ask you if you want 10 million chips 1st month or 50 million.
cowie
I think when they start sendin samples its like a beta game pretty much its what you are going to get unless it something very weird.
pinout and all things needed to implement this ram to your hardware is out.
\they could be making cards with this ram already
pdf that was updated with Ball Assignments and Descriptions
https://www.micron.com/parts/dram/gddr5/mt58k256m32ja-120?pc={A3DEA33E-FC34-4856-9365-52D6D71B95BA}
PrMinisterGR
You both have very valid points, we'll see at around May. I believe that whoever launches with GDDR5x will do so with "soft" launches. We'll see.
evilkiller650
GhostXL
PrMinisterGR
GameWorks is there to create a separate software ecosystem by exploiting the dominance of NVIDIA hardware sales in the last year, increasing those sales in return. Don't read to much more into it really. Whatever they open sourced is already optimized for, more or less.
AMD is going for "open" because they really have no choice at this point, although they tend to be more friendly in the ecosystem than NVIDIA is (they are not known as the Graphics Mafia after all ๐ )
norton