Hyper-threading and Primegrid LLR

I had my new i7-3770 on an Asus P8Z77M-Pro motherboard set up and running for the Primegrid SR5 challenge ... and then noticed something rather sad. My Pentium G850 was completing individual work-units quicker and overall my Core2Quad Q8200 was doing more work per hour. The Xeon E31220 (with a similar benchmark) was doing around 3 times the amount of work per hour.

I started disabling all the 'smart-step' settings in the BIOS and even re-flashed to the latest version. The problem persisted, so I checked the OS and couldn't find any scaling. The CPU temperature showed around 58'C and I couldn’t find any stray processes that were hogging the CPU.
As a last resort, I disabled Hyper-threading in the BIOS and suddenly CPU temps kick up to around 65'C and it burns through a work-unit about 10% quicker than the Xeon.
At this stage, I am assuming that the CPU knocks its own frequency down when all the threads are being used?? Whatever the cause, it is going to be a 4-core machine from now on!
I finished in position 199 for this challenge, which isn't too bad

Intel i7

Due to reliability problems with my office computer, I have upgraded to an Intel i7 -3770 @3.4Ghz with 16Gig ram and an SSD. It is running 64-bit Ubuntu 12.04 LTS and at the moment is running with Hyper-threading turned off.
This is going to hopefully speed up the rate at which I can find primes for PrimeGrid.

On the topic of PrimeGrid, as I write this, we are in the middle of their base 5 Riesel "Fathers Day" challenge and I dragged a few of the older machines out of the store-room for the occasion. The obvious down side is that these machines take well over 6hrs to complete a work unit.

It's that time of year

Apart from my home computer in an air-conditioned environment, everything else is turned off :-(

Another Titanic Prime!

From PrimeGrid:


"Congratulations! Our records indicate that a computer registered by you has found a unique prime number. This computer is running BOINC, is attached to the PrimeGrid project, and is assigned to the Sophie Germain Prime Search. What makes this prime unique is that it's large enough to enter the Top 5000 List in Chris Caldwell's The Largest Known Primes Database.
Since you have auto-reporting selected, the following prime was submitted on your behalf:

Added 110379 : 225597278625*2^1290000+1 (388341 digits)

If you have any questions or concerns, please contact us and we will surely resolve any problems"

Bargin HP Proliant DL380 G4

I picked up a used HP Proliant DL380 G4 on Ebay to add to the "farm". This machine comes with two dual-core Xeon 3.4G CPU's and 6Gigs of RAM. It also has six SCSI drives that I have set-up as 3 separate RAID1 volumes.
I have configured it to run Ubuntu 64-bit 12.04 and at the moment it is attached only to PrimeGrid with the hopes of finding another Titanic Prime.
The only hassle is that it is a little on the loud side ...

Something big this way comes...

More details soon!

Top 1000 Titanic Prime discovered with PrimeGrid

"Congratulations! Our records indicate that a computer registered by you has found a unique prime number. This computer is running BOINC, is attached to the PrimeGrid project, and is assigned to the Sophie Germain Prime Search. What makes this prime unique is that it's large enough to enter the Top 5000 List in Chris Caldwell's The Largest Known Primes Database.
Since you have auto-reporting selected, the following prime was submitted on your behalf:
Added 110130 : 180160106877*2^1290000+1 (388340 digits)"