Unsolved
This post is more than 5 years old
13 Posts
2
1143673
XPS 13 (2015) 9343 BIOS limiting SM951 SSD to x2 link width
Update: The A03 to A05 BIOSes work with the SM951, but it seems like the SSD is stuck at x2 link width over PCIe 2.0. This means you'll only get about 750-800MB/s, when the chipset and port is physically capable of x4 (1500-1600MB/s), so a response from a Dell representative would be very helpful.
edwardhchan
7 Posts
0
March 7th, 2015 21:00
I see. I hadn't updated to A01 yet... Well, I ended up returning the XP941 as it was just too expensive to be worth it. I put in a Crucial MX200 500GB drive and it works great at half the price.
bwentzel13
1 Rookie
1 Rookie
•
33 Posts
0
March 8th, 2015 06:00
I want to upgrade the SSD in my XPS 13 (9343) and I'm considering the 512GB Samsung XP941 so I'm very interested in this thread. The differentiating factor between the Crucial MX200 and the XP941 is the potential performance. Have you run any benchmarks and if so, what performance are you seeing?
Christopher E D
1 Rookie
1 Rookie
•
5 Posts
0
March 8th, 2015 12:00
Did you benchmark the XP941 installed in the XPS 13?
Have you had an opportunity to put the SM951 on an X99 board?
Regards, Chris.
bwentzel13
1 Rookie
1 Rookie
•
33 Posts
0
March 8th, 2015 13:00
kblake06, did you ever get the 512GB XP941 to work and if so, what did you need to do?
TIA
clydei
6 Posts
1
March 8th, 2015 13:00
I have run the ATTO benchmark on the XPS 13 with the XP941. The peak read was 828898 and the peak write was 694774.
The original PM851 that came in my XPS 13 peaked at about 520000 read and about 200000 write.
bwentzel13
1 Rookie
1 Rookie
•
33 Posts
0
March 8th, 2015 13:00
clydei, that seems like an incredible boost! Was it noticeable?
clydei
6 Posts
1
March 8th, 2015 14:00
Boot time is improved by somewhere between one and 1.5 seconds, but real world usage is not terribly noticeable.
bwentzel13
1 Rookie
1 Rookie
•
33 Posts
0
March 8th, 2015 14:00
Thanks clydei. I think I'll go with the Crucial MX200 then and save the money. It has the capacity I'm after and is still a performance improvement over the drive that is in the system.
kblake06
3 Posts
1
March 9th, 2015 18:00
Yes, I got it to work using a Windows USB installer. Afterwards I put Linux on it.
ubus
20 Posts
0
April 2nd, 2015 00:00
with bios A03 i could install the sm951 256 gb
but the speed tested is only 750 mb/s read and 780 mb/s write ..?
oRAirwolf
51 Posts
0
April 13th, 2015 02:00
I imagine the lower speeds are because the chipset used with the Broadwell-U only supports PCIe 2.0.
ubus
20 Posts
0
April 13th, 2015 09:00
but put in my MacPro 5.1 (2010) using an adapter for the pcie 2.0 port 4x the sm951 reaches 1250 - 1300 mb/s so the pcie 2.0 using 4 lanes is capable of speeds up to around 1300 mb/s,
may be the m.2 port inside the XPS 13 2015 uses pcie 2.0 2x / 2 lanes ? or is there a "low power state" as the sandra tool is telling
it would be nice if a Dell representative could answer this question ...
oRAirwolf
51 Posts
0
April 13th, 2015 21:00
The standards for M.2 dictate that the M.2 slot has access to 4 PCIe lanes:
jucytecdesign
7 Posts
0
April 13th, 2015 21:00
Similar issues here:
en.community.dell.com/.../19626427
ubus
20 Posts
0
April 14th, 2015 01:00
this is what sandra tells:
General Capabilities
Model : SAMSUNG MZHPV256HDGL-00000
Manufacturer : Samsung
Height : M.2/NGFF
Interface : NVMe
SSD : Yes
Revision : BXW2500Q
System Bus 3
Type : PCIe 2.00 x2 5Gbps
Multiplier : 3x
Bridge : Intel Wildcat Point-LP PCI Express Root Port #6
Device Connected : Samsung Standardmäßiger SATA AHCI- Controller
Performance Enhancing Tips
Warning 1204 : Link speed lower than maximum supported. Device may be in low-power mode
ist there a way to assign x4 lanes or is it hardwired ?