Installed more RAM - Abysmally slow

Jerad_T

Commendable
Mar 22, 2016
1
0
1,510
Hey all,

I have just installed more RAM into my new PC and its running incredibly slow. I've done research about it and I can't seem to figure it out. I bought this when i built the computer a month ago:

G.SKILL Ripjaws V Series 8GB (2 x 4GB) 288-Pin DDR4 SDRAM DDR4 2400 (PC4 19200) Intel Z170 Platform / Intel X99 Platform Desktop Memory Model F4-2400C15D-8GVR

And another set that arrived today. Upon installing them the computer is now suuuuuper slow. I've tried switching out sets, and slots and when I run one set by itself it works super fast like normal but when i put both in there its back to a crawl. When I take out one stick alone out of the non-home slots and just run 12gigs its back to lightning fast. Is it something with the 4 stick set up in bios? I am running a xmp profile for the timing and settings of the card. CPUz says im running the DRAM frequency at 1199.5MHz and the SPD profile is:
Frequency:1200MHz
CAS# Latency 15.0
RAS# to CAS# 15
RAS# Precharge 15
tRAS: 35
tRC: 50
voltage 1.2

Even doing the auto profile has things running the same.

Motherboard is:
ASRock Z170 Pro4S LGA 1151 Intel Z170 HDMI SATA 6Gb/s USB 3.0 ATX Intel Motherboard
4 slots of memory supposedly supporting 64 gigs max.
Why is that 4th stick causing problems? I know 12 will get me by more than enough with what I'm doing....but its the principle of staring at that 4th stick on my shelf doing nothing....you know?
 
Solution
Start with the original sticks in slots 1-3, go into BIOS, enable XMP, profile 1. Next change the DRAM voltage to 1.3 manually, save, exit shutdown and add the two new sticks and give it a try