I read all forums/websites about ssd pcie for the 9943. And I hope we will receive a nice update to be able to put M.2 SSD PCIE AHCI or NVME without troubles. But I'm thinking about it... I see in different web sites "Dell said it has plans to release a PCIe-based SSD for the XPS 13 soon" So maybe it is not a good deal for Dell to unlock 9943 ???
Sorry Khalid, but you are clearly wrong in almost every single figure you have provided.
If this port was SATA-only it would be limited to 550MB/s, not 750MB/s, and the SM951 would not function at all. The SM951 does not support a SATA interface over PCIe. Both the physical port and the internal buses in the Broadwell platform controller are capable of PCIe 2.0 x4, so the SM951 can do 1500MB/s in the XPS 13 with a future firmware update. The only problem we are having is that the power saving functionality is limiting us to PCIe 2.0 x2. I can confirm that the SM951 does not expose itself to the XPS 13 as a SATA device.
I have no idea where you got 1100MB/s from for PCIe 2.0 x4, but that is wrong as well. I am currently using a PCIe 2.0 x4 M.2 adapter on my PCIe 2.0 desktop and I am getting 1550MB/s from the SM951.
Also, you clearly copied your "max throughput" for PCIe 3.0 x4 from the spec sheet of the SM951. PCIe 3.0 x4 is capable of 3750MB/s, not 2150MB/s (of course the fastest SM951 SSD will only get you 2150MB/s, but that is not the maximum interface throughput). This is also completely beside the point as the chipset in the XPS 13 is PCIe 2.0-only.
This problem is solvable with a firmware update for the XPS 13. Dell has not provided such update or any official response as to if they ever plan on providing it.
The SM951 does not work over SATA, so you are clearly wrong that this port only provides a SATA interface. If the M.2 socket in the XPS 13 was SATA-only would be B-key. The M.2 socket in the XPS 13 is M-key, and I can use it with non-SATA AHCI SSDs.
Just as eligrey stated above, you're completely wrong. If you'd like real proof, I'm getting 750MB's right now out of my 951. We need Dell to enable all 4 lanes and we'll have 1500MB of bandwidth available.
I feel that there is confusion about the M.2 connectivity in the XPS 13 2015 laptop and I just want to demystify it. M.2 is a slot type that can accept multiple types of I/O cards that have different functionalities similar to the expansion slots found in the desktop PC (e.g. PCI, PCIe and etc.). And although this slot can accept multiple types of I/O cards, it has a major difference when compared to the expansion slots found in the PC where the user cannot install any M.2 card in the slot even if it fits on it because only motherboard manufacturer can dictate the correct M.2 card that can work on this slot. You will find, for example, laptops with multiple M.2 slots that will accept different type of M.2 cards and you cannot swap the cards between the slots although they are identical in shape. One could accept an M.2 wireless card while the other could accept an SDD disk. So to sum up, M.2 is an expansion slot similar to the one found in desktop computer but each slot can accept certain type of M.2 cards specified by the motherboard manufacturer.
Having said that, let's now focus on the M.2 SSD card. There are currently multiple types of M.2 SSD flash disk as follow:
1) M.2 SSD Flash Disk with SATA III interface and AHCI protocol.
Theoretically, the maximum throughput for these M.2 cards should be as follow:
1) M.2 SSD SATA III up to 550MB 750 MB/s
2) M.2 SSD PCIe Gen 2 x4 AHCI up to 1100MB 2 GB/s
3) M.2 SSD PCIe Gen 3 x4 AHCI up to 2150MB 4 GB/s
4) M.2 SSD PCIe Gen 3 x4 NVMe up to 2150MB 4 GB/s
Now after this introduction about the M.2 slots and cards, let’s come back to the XPS 13 2015 laptop. The compatible M.2 SSD disk for this laptop is the 1st one (M.2 card that is M.2 SSD SATA III) that can deliver up to 550MB 600MB of throughput. However, since M.2 PCIe interface is backward compatible with SATA, type 2, 3 and 4 should work (Sometime will require BIOS update) but without any performance gain as it will be limited by the SATA III interface throughput. There is no native M.2 PCIe interface yet in this model (There are rumors that Dell will introduce new models with this interface later this year).
Bottom line:
1) Don’t waste your time and efforts by waiting for a BIOS update that will do the miracle of changing the internal connectivity of the M.2 slot from SATA III interface to PCIe.
2) Don’t waist your money by buying expensive M.2 SSD PCIe (AHCI or NVMe) disk while your system can natively work with M.2 SSD disk with SATA III interface.
You can find more information about the subject in below links:
Hi Eligrey and thank you for your elaboration in the subject.
If you allow me, I'd like to discuss your comments.
(1)============================
"If this port was SATA-only it would be limited to 550MB/s, not 750MB/s, and the SM951 would not function at all. The SM951 does not support a SATA interface over PCIe. Both the physical port and the internal buses in the Broadwell platform controller are capable of PCIe 2.0 x4, so the SM951 can do 1500MB/s in the XPS 13 with a future firmware update."
M.2 PCIe SSD cards are backward compatible with SATA protocol. This means if you plug PCIe SSD like the SM951 in M.2 slot configured for SATA it should work but with SATA performance limitation. The M.2 SSD card that comes by default with the XPS 13 notebook is M.2 SSD with SATA III protocol such as Samsung PM851 or Lite-On L8T-256L9G (See the ifixit teardown for XPS 13 https://www.ifixit.com/Teardown/Dell+XPS+13+Teardown/36157). This means the M.2 slot that comes with XPS is capable of SATA III and can accept any M.2 PCIe SDD in compatibility mode.
“In addition to the different physical sizes, M.2 drives are further complicated by the fact that different M.2 drives connect to the system through three different kinds of logical interfaces. Currently, M.2 drives can connect through either the SATA controller or through the PCI-E bus in either x2 or x4 mode. The nice thing is that all M.2 drives are all backwards compatible with SATA so any M.2 drive should work in a M.2 socket that uses SATA - although they will be limited to SATA speeds.”
Used for PCI Express SSDs and interfaced through the AHCI driver and provided PCI Express lanes, providing backward compatibility with widespread SATA support in operating systems at the cost of not delivering optimal performance by using AHCI for accessing PCI Express SSDs”
(2)============================
“The only problem we are having is that the power saving functionality is limiting us to PCIe 2.0 x2. I can confirm that the SM951 does not expose itself to the XPS 13 as a SATA device.”
I’d appreciate if you can proof this
(3)============================
“I have no idea where you got 1100MB/s from for PCIe 2.0 x4, but that is wrong as well. I am currently using a PCIe 2.0 x4 M.2 adapter on my PCIe 2.0 desktop and I am getting 1550MB/s from the SM951.
Also, you clearly copied your "max throughput" for PCIe 3.0 x4 from the spec sheet of the SM951. PCIe 3.0 x4 is capable of 3750MB/s, not 2150MB/s (of course the fastest SM951 SSD will only get you 2150MB/s, but that is not the maximum interface throughput). This is also completely beside the point as the chipset in the XPS 13 is PCIe 2.0-only.”
You are right. Since I mentioned the word “theoretical” I should be providing the theoretical maximum that the bus can achive. I’ll edit this on my previous post and below are references about the M.2 SATA and PCIe speed.
"Hey guys, just wanted to update my last comment with some new information regarding the different 'B' and 'M' keys.
The official M.2 specs are such that the way the drive is keyed is not enough to determine if it's PCIe or SATA based, although with the current drives available on the open market you can still use that as a reliable guide.
At present, in-production M.2 drives with both an 'M' and 'B' key are SATA based, but they could also be PCIe x2 or x4, depending on how they are wired. So determining the type of drive you have installed, and a compatible upgrade, will require careful examination of the existing drive specifications, plus your system specifications, to check if the M.2 SSD socket in your system supports SATA or PCIe SSD's."
Just to add to this discussion, there are many websites that designated the M.2 Slot in the XPS 13 as SATA III compatible and not PCIe AHCI.
Honestly I'm open to any fact that the built-in M.2 is native PCIe and I'll modify my initial post accordingly. I have never come across any compatibility list in the web that mentioned XPS 13 as supported or compatible with M.2 native PCIe AHCI. Software HDD benchmark can be sometime misleading and can provide wrong result especially for SSD disks.
Again I'll be not strictly tied to my initial opinion that M.2 in XPS is SATA if I get a feasible proof that it is PCIe capable or a word from Dell that demystify this.
I noticed in the specification manual two posts above that it lists both Intel HD Graphics 5500 and Intel HD Graphics 6000. I had believed the machine has Intel HD 5500. Does anyone know if the 1920 X 1080 machine has the Intel HD 5500 and the 3200x 1800 touchscreen machine has the Intel HD 6000?
ubus
20 Posts
0
July 23rd, 2015 07:00
With pcie 2 and 4 Lanes this could be the best subnotebook today - so it's the machine with the best display - limited by a weak ssd.
Sypher514852
2 Posts
0
July 24th, 2015 13:00
I read all forums/websites about ssd pcie for the 9943. And I hope we will receive a nice update to be able to put M.2 SSD PCIE AHCI or NVME without troubles.
But I'm thinking about it... I see in different web sites "Dell said it has plans to release a PCIe-based SSD for the XPS 13 soon" So maybe it is not a good deal for Dell to unlock 9943 ???
eligrey
13 Posts
3
July 27th, 2015 16:00
Sorry Khalid, but you are clearly wrong in almost every single figure you have provided.
If this port was SATA-only it would be limited to 550MB/s, not 750MB/s, and the SM951 would not function at all. The SM951 does not support a SATA interface over PCIe. Both the physical port and the internal buses in the Broadwell platform controller are capable of PCIe 2.0 x4, so the SM951 can do 1500MB/s in the XPS 13 with a future firmware update. The only problem we are having is that the power saving functionality is limiting us to PCIe 2.0 x2. I can confirm that the SM951 does not expose itself to the XPS 13 as a SATA device.
I have no idea where you got 1100MB/s from for PCIe 2.0 x4, but that is wrong as well. I am currently using a PCIe 2.0 x4 M.2 adapter on my PCIe 2.0 desktop and I am getting 1550MB/s from the SM951.
Also, you clearly copied your "max throughput" for PCIe 3.0 x4 from the spec sheet of the SM951. PCIe 3.0 x4 is capable of 3750MB/s, not 2150MB/s (of course the fastest SM951 SSD will only get you 2150MB/s, but that is not the maximum interface throughput). This is also completely beside the point as the chipset in the XPS 13 is PCIe 2.0-only.
This problem is solvable with a firmware update for the XPS 13. Dell has not provided such update or any official response as to if they ever plan on providing it.
The SM951 does not work over SATA, so you are clearly wrong that this port only provides a SATA interface. If the M.2 socket in the XPS 13 was SATA-only would be B-key. The M.2 socket in the XPS 13 is M-key, and I can use it with non-SATA AHCI SSDs.
PACougar
4 Posts
0
July 27th, 2015 16:00
Just as eligrey stated above, you're completely wrong. If you'd like real proof, I'm getting 750MB's right now out of my 951. We need Dell to enable all 4 lanes and we'll have 1500MB of bandwidth available.
Khalid11
3 Posts
0
July 27th, 2015 16:00
I feel that there is confusion about the M.2 connectivity in the XPS 13 2015 laptop and I just want to demystify it. M.2 is a slot type that can accept multiple types of I/O cards that have different functionalities similar to the expansion slots found in the desktop PC (e.g. PCI, PCIe and etc.). And although this slot can accept multiple types of I/O cards, it has a major difference when compared to the expansion slots found in the PC where the user cannot install any M.2 card in the slot even if it fits on it because only motherboard manufacturer can dictate the correct M.2 card that can work on this slot. You will find, for example, laptops with multiple M.2 slots that will accept different type of M.2 cards and you cannot swap the cards between the slots although they are identical in shape. One could accept an M.2 wireless card while the other could accept an SDD disk. So to sum up, M.2 is an expansion slot similar to the one found in desktop computer but each slot can accept certain type of M.2 cards specified by the motherboard manufacturer.
Having said that, let's now focus on the M.2 SSD card. There are currently multiple types of M.2 SSD flash disk as follow:
1) M.2 SSD Flash Disk with SATA III interface and AHCI protocol.
- http://www.amazon.com/Samsung-850-EVO-3-5-Inch-MZ-N5E500BW/dp/B00TGIW1XG/
- http://www.amazon.com/Transcend-MTS800-Solid-State-TS512GMTS800/dp/B00KLTPVV8/
2) M.2 SSD Flash Disk with PCIe Gen 2 x4 interface with AHCI protocol.
- http://www.amazon.com/Samsung-XP941-512GB-AHCI-80mm/dp/B00JOSM3TK
3) M.2 SSD Flash Disk with PCIe Gen 3 x4 interface with AHCI protocol.
- http://www.amazon.com/Samsung-SM951-256GB-AHCI-MZHPV256HDGL-00000/dp/B00VELD92U/
- http://www.amazon.com/Eluktro-Pro-X-Performance-TRO-PCIe512GBPRO-X-Eluktronics/dp/B010800UGK/
4) M.2 SSD Flash Disk with PCIe Gen 3 x4 interface with NVMe protocol.
- http://www.storagereview.com/samsung_sm951nvme_m2_ssd_review
- http://www.thessdreview.com/our-reviews/samsung-sm951-m-2-pcie-ssd-review-256gb-nvme-performance/
Theoretically, the maximum throughput for these M.2 cards should be as follow:
1) M.2 SSD SATA III up to 550MB 750 MB/s
2) M.2 SSD PCIe Gen 2 x4 AHCI up to 1100MB 2 GB/s
3) M.2 SSD PCIe Gen 3 x4 AHCI up to 2150MB 4 GB/s
4) M.2 SSD PCIe Gen 3 x4 NVMe up to 2150MB 4 GB/s
Now after this introduction about the M.2 slots and cards, let’s come back to the XPS 13 2015 laptop. The compatible M.2 SSD disk for this laptop is the 1st one (M.2 card that is M.2 SSD SATA III) that can deliver up to 550MB 600MB of throughput. However, since M.2 PCIe interface is backward compatible with SATA, type 2, 3 and 4 should work (Sometime will require BIOS update) but without any performance gain as it will be limited by the SATA III interface throughput. There is no native M.2 PCIe interface yet in this model (There are rumors that Dell will introduce new models with this interface later this year).
Bottom line:
1) Don’t waste your time and efforts by waiting for a BIOS update that will do the miracle of changing the internal connectivity of the M.2 slot from SATA III interface to PCIe.
2) Don’t waist your money by buying expensive M.2 SSD PCIe (AHCI or NVMe) disk while your system can natively work with M.2 SSD disk with SATA III interface.
You can find more information about the subject in below links:
- http://www.pcper.com/reviews/Storage/PCIe-SSD-Roundup-Samsung-SM951-NVMe-vs-AHCI-XP941-SSD-750-and-More
- https://www.youtube.com/watch?v=u-kACJLKNOI
- http://arstechnica.com/gadgets/2015/02/understanding-m-2-the-interface-that-will-speed-up-your-next-ssd/
- https://www.pugetsystems.com/labs/articles/Overview-of-M-2-SSDs-586/
Sypher514852
2 Posts
0
July 27th, 2015 18:00
Can you show us printscreens ? So we can all agree.
clydei
6 Posts
0
July 27th, 2015 21:00
Samsung XP941 in my XPS 13.
Clearly better than sata but no where near what it should be.
aemitic
4 Posts
0
July 28th, 2015 04:00
Thank you eligrey for the clarifications!!
This means that very likely Dell could provide a firmware update to enable all x4 lanes.
Can someone from Dell please respond? An official answer would be very very appreciated.
Thanks very much
Khalid11
3 Posts
0
July 28th, 2015 14:00
Hi Eligrey and thank you for your elaboration in the subject.
If you allow me, I'd like to discuss your comments.
(1)============================
"If this port was SATA-only it would be limited to 550MB/s, not 750MB/s, and the SM951 would not function at all. The SM951 does not support a SATA interface over PCIe. Both the physical port and the internal buses in the Broadwell platform controller are capable of PCIe 2.0 x4, so the SM951 can do 1500MB/s in the XPS 13 with a future firmware update."
M.2 PCIe SSD cards are backward compatible with SATA protocol. This means if you plug PCIe SSD like the SM951 in M.2 slot configured for SATA it should work but with SATA performance limitation. The M.2 SSD card that comes by default with the XPS 13 notebook is M.2 SSD with SATA III protocol such as Samsung PM851 or Lite-On L8T-256L9G (See the ifixit teardown for XPS 13 https://www.ifixit.com/Teardown/Dell+XPS+13+Teardown/36157). This means the M.2 slot that comes with XPS is capable of SATA III and can accept any M.2 PCIe SDD in compatibility mode.
-https://www.pugetsystems.com/labs/articles/Overview-of-M-2-SSDs-586/
“In addition to the different physical sizes, M.2 drives are further complicated by the fact that different M.2 drives connect to the system through three different kinds of logical interfaces. Currently, M.2 drives can connect through either the SATA controller or through the PCI-E bus in either x2 or x4 mode. The nice thing is that all M.2 drives are all backwards compatible with SATA so any M.2 drive should work in a M.2 socket that uses SATA - although they will be limited to SATA speeds.”
-https://en.wikipedia.org/wiki/M.2
“PCI Express using AHCI
Used for PCI Express SSDs and interfaced through the AHCI driver and provided PCI Express lanes, providing backward compatibility with widespread SATA support in operating systems at the cost of not delivering optimal performance by using AHCI for accessing PCI Express SSDs”
(2)============================
“The only problem we are having is that the power saving functionality is limiting us to PCIe 2.0 x2. I can confirm that the SM951 does not expose itself to the XPS 13 as a SATA device.”
I’d appreciate if you can proof this
(3)============================
“I have no idea where you got 1100MB/s from for PCIe 2.0 x4, but that is wrong as well. I am currently using a PCIe 2.0 x4 M.2 adapter on my PCIe 2.0 desktop and I am getting 1550MB/s from the SM951.
Also, you clearly copied your "max throughput" for PCIe 3.0 x4 from the spec sheet of the SM951. PCIe 3.0 x4 is capable of 3750MB/s, not 2150MB/s (of course the fastest SM951 SSD will only get you 2150MB/s, but that is not the maximum interface throughput). This is also completely beside the point as the chipset in the XPS 13 is PCIe 2.0-only.”
You are right. Since I mentioned the word “theoretical” I should be providing the theoretical maximum that the bus can achive. I’ll edit this on my previous post and below are references about the M.2 SATA and PCIe speed.
- https://www.pugetsystems.com/labs/articles/Overview-of-M-2-SSDs-586/
- https://en.wikipedia.org/wiki/PCI_Express
(4)============================
“The SM951 does not work over SATA, so you are clearly wrong that this port only provides a SATA interface.”
SM951 should supposedly work over SATA in compatibility mode with prober firmware as mentioned before.
(5)============================
“If the M.2 socket in the XPS 13 was SATA-only would be B-key. The M.2 socket in the XPS 13 is M-key, and I can use it with non-SATA AHCI SSDs.”
This is not valid any more. M-key support PCIe and SATA as well and you cannot judge the card compatibility by checking the slot keying.
- https://www.ramcity.com.au/blog/m.2-ngff-ssd-compatibility-list/189
- https://en.wikipedia.org/wiki/M.2
- http://www.mydigitaldiscount.com/m.2-ngff-ssd-compatibility-list.html
"Hey guys, just wanted to update my last comment with some new information regarding the different 'B' and 'M' keys.
The official M.2 specs are such that the way the drive is keyed is not enough to determine if it's PCIe or SATA based, although with the current drives available on the open market you can still use that as a reliable guide.
At present, in-production M.2 drives with both an 'M' and 'B' key are SATA based, but they could also be PCIe x2 or x4, depending on how they are wired. So determining the type of drive you have installed, and a compatible upgrade, will require careful examination of the existing drive specifications, plus your system specifications, to check if the M.2 SSD socket in your system supports SATA or PCIe SSD's."
Just to add to this discussion, there are many websites that designated the M.2 Slot in the XPS 13 as SATA III compatible and not PCIe AHCI.
- http://www.mydigitaldiscount.com/m.2-ngff-ssd-compatibility-list.html
- http://laptopmedia.com/laptop-m-2-ngff-ssd-compatibility-list/
- http://www.crucial.com/usa/en/compatible-upgrade-for/Dell/xps-13-ultrabook
PACougar
4 Posts
0
July 28th, 2015 15:00
You seem to be ignoring the fact that we're not getting Sata speeds through the port with our 951's.
Khalid11
3 Posts
0
July 28th, 2015 15:00
Hi PACOUGAR.
Honestly I'm open to any fact that the built-in M.2 is native PCIe and I'll modify my initial post accordingly. I have never come across any compatibility list in the web that mentioned XPS 13 as supported or compatible with M.2 native PCIe AHCI. Software HDD benchmark can be sometime misleading and can provide wrong result especially for SSD disks.
Again I'll be not strictly tied to my initial opinion that M.2 in XPS is SATA if I get a feasible proof that it is PCIe capable or a word from Dell that demystify this.
Christopher E D
1 Rookie
•
5 Posts
0
July 28th, 2015 15:00
Hi, I am attaching a link to the XPS 13 9343 specifications manual from Dell, Dell clearly thinks they implemented SATA 3 for an M.2 SSD.
Regards, Chris.
downloads.dell.com/.../xps-13-9343-laptop_Reference%20Guide_en-us.pdf
bernito8
2 Posts
0
July 28th, 2015 16:00
I noticed in the specification manual two posts above that it lists both Intel HD Graphics 5500 and Intel HD Graphics 6000. I had believed the machine has Intel HD 5500. Does anyone know if the 1920 X 1080 machine has the Intel HD 5500 and the 3200x 1800 touchscreen machine has the Intel HD 6000?
aemitic
4 Posts
0
July 31st, 2015 01:00
Can someone please verify if the new bios version A05 unlocks the PCIe x4 lanes?
Thanks
PACougar
4 Posts
0
July 31st, 2015 09:00
It doesn't.