U.S. ATLAS HL-LHC Upgrade Level 2 and Deputies-NSF only Management Mailing List

["Zhang, Jinlong" <zhangjl AT anl.gov>]

Agreed.

> On Aug 28, 2019, at 2:40 AM, Gustaaf Brooijmans 
> <gusbroo AT nevis.columbia.edu> wrote:
> 
> 
> Hi,
> 
> The possibility of such an alternative approach is why we put in the 
> "architecture change" risk.  The example reasons we give are different, but 
> that doesn't matter.  Basically we expect to make similar labor and 
> material investment.  I adjusted the current sentence to
> 
> "ATLAS continues to investigate commodity hardware and hybrid options, but 
> HTT is the baseline plan.  If at some point a hybrid or commodity-based 
> solution were to become clearly preferred, then we would contribute to that 
> at a level similar to our current plan, both in terms of labor and 
> materials.  (See also risk RN-06-08-02-019.)"
> 
> I believe that statement to be true.
> 
> Best,
> 
> Gustaaf
> 
> 
> On 8/27/19 9:17 PM, Zhang, Jinlong wrote:
>> Hi Elliot,
>>> 
>>> On the alternatives, there has been a lot of progress on the CPU-base 
>>> tracking which makes it at least plausible now, but I think there are 
>>> still space and power challenges there. This requires abandoning the 
>>> evolution option. They would need to come up with a lot of money (similar 
>>> to HTT) for hardware.
>>> 
>> According the study, space and power is not a problem, money wise is not 
>> even close to HTT. The working group document is in progress. So maybe 
>> safer not to make statements on these, but just say technology wise this 
>> is plausible.