I have WBT & 4DS so I am relatively impartial, but the stupidity...

I have WBT & 4DS so I am relatively impartial, but the stupidity of your comments is really starting to grate. Your apparent complete ignorance of how memories work and in particular 4DS's history and memory milestones is simply annoying. Give it a rest because you are embarrassing yourself and every other WBT holder. You are making us look like children and I don't want to be associated withy your behaviour.

Firsty, the 4DS 40nm memory cell tests were outstanding successes when they were done some years ago, and the retention issue relates to how long between cycles the refresh is required. The early persistence testing showed very long cycles, but the upper limits were not established, just that they could exceed the timeframes they tested. For the megabit array proof of concept stage, the IMEC megabit array controller and fab could only get to 60nm at IMEC so that is what they used for the proof of concept stage per WD's requirements. Just like WBT is certified and temp tested at 130nm but the cells have been tested at 20nm - just not in an array with a controller. The memory was originally planned as NVRAM which they discovered could achieve DRAM speeds (unlike the WBT memory which has fast read but really slow write) with staggeringly high endurance when they tested the cells so a previously unexpected market opened up and thus they switched from focussing on retention optimisation as an NVRAM to focussing on speed, endurance and power consumption, based on what WD said they wanted. They provided the performance spec requirements, so that is what 4DS focussed on and had to prove in the megabit array.

Now they are clearly turning to the next two issues: proof of concept on a smaller geometry megabit array and persistence, but from this point going forward they are a takeover candidate as they have achieved the minimum proof of concept required by a major manufacturer. The longer the company persists developing the tech from now the more expensive the company becomes for a buyer, so it becomes a risk balancing game for the memory manufacturers: Do they take on the risk of tech finalisation themselves now, at a lower buy price, or do they let 4DS continue to develop and pay a higher premium later, or risk losing access to the tech entirely.

WBT & 4DS have different market focusses and different sweet spots. Both have a place and both are relevant, but they have very different commercialisation strategies, different required end points and fundamentally different approaches and characteristics for the memory design problem. Comparing the two is stupid. One is not "better" than the other - just different.

Please stop the embarrassing cross-company forum trolling.