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 2015-08-01, 17:26 #1 wildrabbitt   Jul 2014 3×149 Posts memory for budget machine Hi guys, building a machine on a budget. Going for another FX6300 to do p > 80000000 tests. As I understand it the LL test doesn't benefit from a lot a memory. Will 2GB DDR3 be enough or would it be silly / problematic?
 2015-08-01, 17:53 #2 Prime95 P90 years forever!     Aug 2002 Yeehaw, FL 23×7×137 Posts I strongly recommend an Intel CPU for LL testing.
 2015-08-01, 18:03 #3 wildrabbitt   Jul 2014 1BF16 Posts I can't change my preference for AMD CPU's until I understand why Intel's are better. I've asked before but was not replied to.
 2015-08-01, 18:05 #4 Batalov     "Serge" Mar 2008 Phi(4,2^7658614+1)/2 100101100010002 Posts The answer is simple. AVX2, FMA.
 2015-08-01, 18:13 #5 wildrabbitt   Jul 2014 3·149 Posts Can I get an intel 6-core at 3.5 GHz for £80 pounds? What's the best bet for a £100 intel processor?
2015-08-01, 18:15   #6
VBCurtis

"Curtis"
Feb 2005
Riverside, CA

5·1,013 Posts

Quote:
 Originally Posted by wildrabbitt I can't change my preference for AMD CPU's until I understand why Intel's are better. I've asked before but was not replied to.
Have a look at the benchmarks page, see for yourself. If you want to get LL work done, Intel crushes AMD. If you pay for electricity, work per watt is yet better for Intel. There may be a purchase-price point where an AMD can do almost as much work as an Intel, but at 3x the power cost.

More work for less power, and not much more $upfront. Edit: FX-6300 benchmark at 4k FFT is 108 (I think that's ms/iter). An i3 at 3.5ghz is 30. So, two cores of i3 achieve more work than 6 cores of 6300, at roughly 1/3rd the system power. Last fiddled with by VBCurtis on 2015-08-01 at 18:23  2015-08-01, 18:32 #7 Batalov "Serge" Mar 2008 Phi(4,2^7658614+1)/2 23×1,201 Posts When thinking about AMD for use with P95, one has to keep one simple thought in mind - FX-6300 is a 3-core for P95. Not a six-core. And the same for all other products in that AMD line: "8-cores" a 4-cores, "4-cores" are 2-cores. For ~100 pounds, you can get something like a i5-4590 and for a little more, a i5-4690K, or something similar. There is plenty to choose from.  2015-08-01, 20:57 #8 wildrabbitt Jul 2014 44710 Posts I run 6 LL tests at a time on my FX6300's. Anyway, suppose I get a ~£100 intel CPU. Will I still get by on 2 or 4GB of RAM ? 2015-08-01, 21:15 #9 henryzz Just call me Henry "David" Sep 2007 Cambridge (GMT/BST) 5·1,187 Posts Quote:  Originally Posted by wildrabbitt I run 6 LL tests at a time on my FX6300's. Anyway, suppose I get a ~£100 intel CPU. Will I still get by on 2 or 4GB of RAM ? Assuming windows 2GB would run. If you plan to use the system as well for browsing etc I would highly recommend 4GB. 4GB would be a minimum for me.  2015-08-01, 21:17 #10 Batalov "Serge" Mar 2008 Phi(4,2^7658614+1)/2 23×1,201 Posts You want to save less than £10 ? 2x2Gb costs ~$33 and 2x4Gb costs ~\$45 here. (e.g. in DDR3 1866 category) Is it worth it? You may read some reviews that argue that single-channel vs dual channel makes no difference, but for some reason they never include P95 in benchmarks. Anyway, for P95 (or LLR etc), it matters, contrary to those reviews.
2015-08-01, 22:25   #11
VBCurtis

"Curtis"
Feb 2005
Riverside, CA

117118 Posts

Quote:
 Originally Posted by wildrabbitt I run 6 LL tests at a time on my FX6300's. Anyway, suppose I get a ~£100 intel CPU. Will I still get by on 2 or 4GB of RAM ?
When you run 6 tests at once, how long does a single test take? When you run just 3 tests, how long does each test take? We're pretty sure the second answer is very close to half the first answer.

But, if you like, you can run 12 tests at once. Pretty sure it's not faster, either.

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