In this article we return to memory speed and its effect on PC performance in real-life applications. Last time we were interested in Phenom X4 9850. Today we'll analyze a top processor from the other company -- Intel Core 2 Extreme QX9770. We decided to leave test conditions as they were in the previous review: first we run tests with fast memory, then we halve memory frequency in BIOS and run tests again.

In order to preserve the principle of reducing memory frequency precisely by half, we ran first tests with DDR3-1600 memory (800 MHz), even though our memory modules could do better. However, we witnessed an interesting effect: having compared results of the QX9770 processor with DDR3-1800 and DDR3-1600 memory, we found out that the latter turned out to perform... better. Probably owing to better "synchronism" of memory and FSB frequencies. For that matter we did a "silent update" of QX9770 results in this review. So if you want to see where QX9770 wins another point or two, you are welcome.

So, the second round of tests was run with DDR3-800 memory. Some of our readers may note that such memory makes no practical sense at all. But in this case we are not interested in practical sense, we just recreate a situation, when CPU's access to memory is artificially slowed down twofold, so our choice is well justified. It goes without saying that we use our Corsair CMX3X1024-1800C7DIN memory modules, we just modified their operating frequency in BIOS.

Tests

As always in such cases, we are particularly but not exclusively interested in performance results obtained in real-life applications, so we replaced diagrams with tables again, and virtual points with raw test results. The "Gain" column shows performance gains for Intel Core 2 Extreme QX9770. The "X4 9850" column shows performance gains, demonstrated in similar conditions by AMD Phenom X4 9850.

3D modeling and rendering

It's worth mentioning an unusual 4% render performance gain on QX9770. As a rule, render speed does not depend much on memory bandwidth. In other respects, Intel and AMD processors demonstrate similar performance gains in the same tests. By the way, their performance gains are far from huge.

CAD/CAM

Both QX9770 and X4 9850 demonstrate the average performance gain of 3%, but this result is formed differently in each case: the X4 9850 gets the biggest gain in the graphics part of UGS NX test, while the Intel system accelerates noticeably in the CPU test of SolidWorks. We are not aware of any "commentable" details in this case, so we'll just write it off to "application specifics".

Compiling

The system based on the processor from Intel is less sensitive to memory performance. Probably owing to larger caches.

Professional photo processing

Adobe Photoshop takes advantage of faster memory more effectively with the QX9770 processor -- twice as efficiently as with Phenom X4 9850. Alas, "twice as efficiently" in this case means just 6% versus 3%, that is very little at best.