Precision 7710 Memory Upgrade Options

I've been experimenting to see if I could increase the performance of a recently acquired Dell 7710 equipped with a soldered in place 6820HQ cpu.

Having had some success in the past with faster memory upgrades on 6440 laptops, I thought it worth a try.

My 7710 shipped with 2x2133Mhz 16GB Samsung modules in the slots under the keyboard. The laptop ran well on this so I tried to find faster RAM while maintaining the 32GB capacity.

1) 2x8GB 2666Mhz

The first test was to see if 2666Mhz RAM would be recognised by the BIOS and the cpu's memory controller and run without problems.

I used Iveco 2666Mhz modules which were fairly cheap, (used on ebay) as the first test.

The system booted up and ran perfectly on the new RAM. Noticeably snappier too and userbenchmark confirmed the increased RAM performance.

2) 4x8GB 2666Mhz CL 19

The 7710 manual states that a maximum of 32GB of higher speed RAM spread across all 4 slots can be fitted.

The system booted up and ran beautifully in the extra RAM.

Please note that the 4 RAM modules were carefully sourced to be a part number match to enhance the prospect of success.

I could (should!) have stopped there, but I noticed the RAM had quite a relaxed CAS Latency of 19. This is good for compatibility but not performance.

3) 4x8GB 2666Mhz CL 15

The fastest RAM I could find at 2666Mhz was HyperX with a CAS Latency of 15. Things had gone so smoothly and the system hadn't missed a beat so definitely worth a try.

The system wouldn't boot to the BIOS screen. A few plaintive beeps and flashing lights but not able to start.

4) 2x8GB 2666Mhz CL15

As running four high speed, low latency DIMMs was asking a lot of the 7710, I thought I'd try using two.

This configuration booted up and ran beautifully and is the configuration I'm now using day to day.

5) 2x8GB 2666Mhz CL15, 2x8GB 2666Mhz CL16

Maybe if I eased the RAM timings down a little from CL15 to CL16. Crucial sell CL16 2666Mhz modules so worth a try to get back to 32GB of RAM.

System booted up ok, it took a while for the BIOS to sort out the memory configuration and away it all went.

Sadly the Crucial modules only provide 2666Mhz via the XMP settings. All of the RAM was slowed down to the 2400Mhz of the Crucial memory's Jedec timings. Not a success, but I did learn that the BIOS was not using XMP settings.

To conclude, I'm running now with 16GB of CL15 2666MHz RAM. The system is noticeably more responsive and the benchmarks do reflect the memory's performance with the CL15 being markedly faster than the CL19.

The inability to support 4 DIMMs at top speed/latency may just be a feature of my motherboard or cpu of course.

I'm interested in other's experiences.

 

I am on 2133 (1067) MHz memory, HyperX on Hynix chips, CL13 (XMP) and CL14 (JEDEC).
CPU-Z reports CL13 1067 (2133).
I am using 4 nearly identical sticks (same specs and brand, 1,5 year difference in production date).
This gives me 12.19ns of access delay.
Switching to 2666 CL15 (mentioned by you HyperX again) would give me 11.25ns (if supported by motherboard), so total of just under 8% gain - in this one kind of memory access.

Do you have some exact benchmark results that would show the gain in performance?