Shadow wrote:
https://www.kabum.com.br/produto/507...d-hx318c10fr-4
https://www.kabum.com.br/produto/507...k-hx318c10fb-4

Other than the price ?

I downloaded the Kingston specs

https://cdn.cnetcontent.com/07/e9/07...f10cf84f67.pdf

Which says:

Latency CL9-11
Voltage 1.35V, 1.5V

It does not help at all in knowing if I can add a stick or
two.

My current memory is KHX1866C10D3/4G
Number of banks 8
Nominal Voltage 1.50 Volts
(CPU-Z output)
TIA
[]'s

Kingston has specs right on their own web site.

50758 HX318C10FR/4 CAS10 1866 1.35V RS220
50759 HX318C10FB/4 CAS10 1866 1.5V RS247

The available information only lists 1.5V products.

https://www.kingston.com/dataSheets/HX318C10FR_4.pdf

The article here suggests the heat spreader color
is for "taste" in PC construction. Four colors are
available in all. The heat spreader color is not intended
as a voltage indicator.

https://www.kingston.com/en/company/press/article/7141

If your retailer is to be believed, then I would
select the 1.5V product to match the 1.5V product I
already have.

Someone had a problem with this very thing in a post
about two days ago. System had two 1.5V DIMMs, poster
added two 1.35V DIMMs. The 1.35V DIMMs (DDR3L) are supposed to
work in 1.5V system, and that's why the keying on the
edgecard of the DIMM allows insertion. However, the
system of the poster would not work.

CH0 CH1 Note: all DIMMs are 4GB

1.5V ---- 1.5V ---- (Dual channel mode)
Failed to POST...
1.35V ---- 1.35V ----

For reasons known only to the BIOS logic, this worked.

CH0 CH1

1.5V ---- 1.35V ---- (Dual channel mode)
Works...
1.5V ---- 1.35V ----

Both of these setups run *all* slots at 1.5V.
The sticks are never "treated as individuals".

The way RAM works, is the environment of all DIMMs
is the same. They receive the Column Address Strobe
(CAS) on the same cycle. They receive the same clock
frequency. They receive the same voltage for their
power source. Since the DIMMs are on shared buses
and the memory controller for both channels comes
from the same chip, there is an incentive to make
all operating conditions identical.

Why inserting the DIMMs as in the second diagram
works, is a mystery. Since the DIMMs are all 4GB
ones of equivalent construction, it allows some
flexibility in mixing. The dual channel works in
both situations. The system is still in dual channel
mode after the change.

A question you would have to ask, is whether the
1.5V RAM you "boost" to 1.65V, whether a 1.35V
RAM can also be boosted to 1.65V. If you do
select the 1.35V RAM, I would do so only for
a system which does not have a high boost for
VDimm. As I don't know the extent of the "tolerance"
on the 1.35V DDR3L.

The 1.35V stuff is readily available, and Kingston
has resorted to "cherry picking" on the DRAM market.
While the spec sheet says 1.5V, Kingston refuses
to make a separate SKU for 1.35V in this case. Kingston
did something similar a few years back, mixing
high density and low density DIMMs under the same
SKU, in violation of their datasheet. (The datasheet
might show double-sided DIMMs, but the blister packs
of memory had single-sided DIMMs in some packages
and double-sided DIMMs in other packages. This
caused *grief* for people seeking low density RAM,
which is what the product was intended for.)

As far as I know, if 1.35V RAM is on a DIMM, the SPD
EEPROM must have an encoding for it. Consequently,
if those two products are for real on your retailer
site, they likely do not have identical SPD contents
when you examine them in CPUZ SPD table. This could
be what is causing the BIOS to fail to set up
some configurations of the mixed RAM. The BIOS was
not programmed to accept "variation" in that field
of the SPD EEPROM.

The general rule of thumb for memory is, to mix
"like with like". Don't mix server ram with
"enthusiast overclocker RAM" as the latter needs
too much voltage for stability. If you start with
server ram at stock voltage, your upgrade to
the system should also be server class RAM
(which runs at JEDEC voltage, not boosted voltage).

If you need to save a few bucks by buying the 1.35V
RAM, you can. But be prepared for the system to black
screen and not POST properly. You may have to send the
RAM back, if your BIOS does not like it. There is no
way to know in advance, whether the BIOS is ready for it.

It's also possible, if the motherboard has a BIOS upgrade,
that the BIOS could be modified to "ignore" the
voltage field. And then any configuration of DIMMs
would work with less trouble than the above example.

HTH,
Paul