- Joined
- Dec 31, 2003
- Location
- rhode island
That quote from Chew warrants more explanation - it is confusing and I was there. The 8.4Ghz chip was probably mostly untested or completely untested if thats what they are saying (not sure which they are saying) - I would believe what they say though. They had to run those chips to get the VID off them obviously though.
So while I was standing next to the table, I'm going by memory here, but they were talking about this after they switched out the first two setups they had on the bench. So I believe this was just before the 3rd setup, and it was the 4th CPU they used for the press demo to try to get the record. I thought it was weird as I was standing there Sami and Brian were discussing what to do next and Sami said something about taking a shot in the dark, just gambling on an untested CPU next. I have no idea if they then grabbed a new CPU from the tray, or picked from the trays and trays of CPUs that had already been tested in some way at least... But I thought that was sort of weird since there were so many chips that had already been tested to some degree. There were a lot with VID marked as well as LN2 pretesting to 8GHz or so labeled and sitting in the trays next to them.
So seeing all the labeled CPUs, clearly there was a lot of testing that went into determining which chips behaved which way. Checking VID and recording clocks and voltage to determine trends in frequency results across chips. AMD had sent out CPUs a week before also, where 8 BD chips hit 8GHz - they didn't say 8 out of how many. That all occurred the week before the event reportedly, simply on LN2. An 8GHz chip on LN2 is going to be a contender with 8.3GHz on LHe.
So the obvious question... If they had been through that many chips in pretesting, they had spent so much time learning about the architecture, how it behaves under cold, and recording results for each chip - Why throw a hail mary at crunch time in front of 20 hand picked journalists, plus me?
Maybe the first best CPU's/boards they just tried failed, had condensation problems, died in pretesting... Dunno, a lot of things can go wrong doing subzero. It doesn't totally make sense to put all that time into pretesting, then when it comes to do or die time take a hail mary pass... So what was the reason? Maybe the VIDs they found to hold the most promise in pretesting was enough to give them an idea of what the chips would do.
Ok here is what i did.
I ran tests previously on various vid chips. I found the lowest vid which was rare really sucked, second lowest not so bad and 3rd from lowest scaled decent.
Taking that info i just VID binned in front of media if you recall and labeled all chips. Post to bios with a profile with all power saving off log voltage remove chip and label simple as that......
After i got tired of testing chips we had 24 total with my personal choice of VID which is the third from lowest so not really what you would call leaky.
We tested all chips at 1.8v ( so as not to damage them ) on ln2, 7.7, second sort of a dud 7.2 third 7.7, 4th hit just under 7.9 and we decided to go under LHe at that time.
As far as personal testing prior to event I think i tested 15 chips including my 2 personal B0 samples which I might add were nothing spectacular. So 13 B2 chips in total.
4 did 8 gig on ln2.......
Now onto why we used an untested chip versus chips we had already tested prior. Quite simple beating on chips at home at 2.0 v on 32nm is bad for a cpu.....at that point it is just a fuse waiting to pop.
I actually pushed one at home purposely that was a 7875 chip to find the breaking limits.....and i found it.
Now i'm not sure about you but LHe tanks are $1000 a wack, you burn quite a bit just getting the pot down to optimal temps. My personal motto for live events is this "Failure is not an option"
Knowing this i'd hate to waste half a tank on a previously beaten on chip and since we knew what we needed clocks and volts wise we knew it would not take much to find more 8 gig chips, 4 out of 15 is preety good odds.....