Discussion in 'Processors and motherboards AMD' started by vbetts, Sep 24, 2018.
What a stupid, pointless test.
Can't these tech amateur reviewers understand that the 7800X3D only ahs one CCD so overclocking memory will always be limited by the Infinity fabric, to around 64GB/s.
Maybe they are hooping there is 7800x3d with two ccd's
btw its a bug
For me it is clearly Limits of IMC of Ryzen.
Same thing is with 5950X - Best is to use 3733-3800 but with max of CL16.
Same thing was occuring in those tests, 3600CL14 was faster in 0.1% than 3800CL14 BTW
According to my internal tests 3800CL16 is the fastest OC for 5xxx, Lows are very good.
He is talking about bandwidth specifically. There is no point overclocking single ccd 7600x/7700x7800x3d when the IF cap is 64gb/s. 7900x/7950x3d dual ccd on the other hand go up to 90+gb/s.
I'm talking a bout the bandwidth of the IF bottlenecking the memory bandwidth.
The 4800X3D has only one CCD, on a 32 bit bus. Even if we get the Infinity Fabric to 2100 Mhz, that's only 67.2 GB/s. Or 64GB/s, for an IF at 2000 Mhz.
Doesn't matter how fast you push the memory, because it will always be limited to that IF speed.
Only dual CCD Zen4 CPUs can benefit from higher memory bandwidth. Because they have 2 CCDs, so it's 2000 Mhz X 2 X 32 Bits = 128GB/s.
If there is anything to gain from that speed, on Zen4, it can only be seen on dual CCD CPUs.
It's ok for a common user to not know this. But a professional reviewer, doing a specific test about memory scaling with speed, has to know this.
What that guy did is completely moronic.
DDR5 6200 - IF 2100 = 66gb/s.
This is mine :
Real world latency is always lower than the theoretical maximum.
But yours is very close to the 67.2 GB/s.
I also didnt know that at first and i actually learned that from you
I leaned it from a professional reviewer. A real professional.
It's also funny how he's straight up copying the Hardware Unboxed format, same "studio" design, same benchmark graphs design etc....
7600x 5.65ghz R23 ST compared to 14600k
He upgraded from 12900k thats a nice bump in performance but i dont see much sense going to 7800x3d if you already own any of the zen4 cpus so close to zen5 release.
Zen5 .. gimme gimme gimme.
I'm ready...I know I am.
Just upgraded to a Corsair 64GB 6000MHz CL30 kit from 32GB (paid equivalent of ~$200 USD after tax great price for us in Australia couldn't resist) and I am surprised that even opening up things like Firefox felt snappier. Is 64Gb the new 32GB lol.
New kit seems to be playing nice with my previously tweaked 6200MHz 30-38-38-30 + Buildzoid's secondary timings so far (I thought the memory settings in bios would've reset itself when I installed the new memory but it kept it) running stress tests right now fingers crossed all is good haha.
I need help. When I manual oc my 7600x it randomly reboots when idle. Even with high voltages like email@example.comV. Its ok in games or benchmarks. Any ideas?
EDIT: Disabled C-states and fast boot, checking if it helped