Kaby Lake Precision pre-release discussion (5520 / 7520 / 7720)

Anyone able to install windows 7 on any of these laptops"?

 

Hi, I have Dell 7720 / i7 7820HQ. I have only one drive: SATA 2.5" SSD installed. I want to add M2 SSD. My question is if this laptop will work with M.2-Sata SSD drive or only with M.2 nvme SSD? I am not sure about it, even after browsing the manual. I would prefer sata m2 (Crucial mx500), because I read that m2/nvme drives slow down during heavy load and high temperature.

 

It will take either type of drive, SATA or NVMe.
NVMe drives can slow down from max performance under load, but they will still be faster than SATA drives.

 

Yes. You will need a Skylake generation CPU for this to work. Then everything will work fine and is also supported by Dell. The 7x20 is the last generation to support this OS. The 7x30 is not supported with Windows 7.

 

I am looking for the best RAM upgrade option to a total of 32 GB. It looks like Kingston HyperX offers the fastest RAM available today:
- HX424S14IB2/8: 2400 MHz, CL14-14-14
- HX426S15IB2/8: 2666 MHz, CL15-17-17

However, Kingston suggests to use its KCP424SS8/8 (2400 MHz, CL17) RAM modules instead. They are slower, cost more than HyperX counterparts and are covered under the shorter warranty period.

1. Why is Kingston recommending KCP for the 7520? Is it really better (more compatible) than HyperX?
2. Has anyone tried using those HyperX modules, are they compatible?
3. Which HyperX module (2400 or 2666 MHz) is faster? If I do not take into consideration 2nd and 3rd timing value, the 2666 MHz one should be faster, but is it really?

 

You can only directly compare CL ratings for modules that operate at the same speed. Otherwise, you should look at comparing CL / SPEED (lower is better), as CL depends on the speed (it is the number of clock cycles for the memory to produce the requested value). The 2666 MHz one is actually faster, but the difference is very small...
(I don't have enough of an understanding of the 2nd and 3rd timing values to understand how they affect performance. Usually they are the same as they are for your first module. Maybe they actually make that one a worse choice.)

 

I had great trouble in upgrading my Precision 7520 memory. After two failed upgrades, Dell support told me that I need exactly the same modules as already installed in my system.
Kaby Lake Precision pre-release discussion (5520 / 7520 / 7720)

In my case: I have 8GB DDR4 2666 modules (Kingston XF875V / Dell part Nr F875V) and I had to buy the same modules from eBay to upgrade from 16 GB to 32 GB. With outer modules, the system refused to boot with a processor failure error. (Processor was and is fine, it was the memory)