Introduction to the HP t640 Thin client - your cheap little AMD NUC7 alternative

[patrick80]

Thank you for the extensive write-up about these machines WANg. I just ordered one of these off ebay. I recently got a few things running on a Raspberry Pi 3, and I'm concerned about the SD card failing and this machine seems to be the perfect upgrade with lots of excess capacity.

Does anyone have a recommendation for memory upgrades? I was just looking at Newegg and Amazon for DDR4-2400 SODIMMS, but there are a variety of CAS latency timings available. Is there anything I should seek out or avoid?

 

[WANg]

Thank you for the extensive write-up about these machines WANg. I just ordered one of these off ebay. I recently got a few things running on a Raspberry Pi 3, and I'm concerned about the SD card failing and this machine seems to be the perfect upgrade with lots of excess capacity.

Does anyone have a recommendation for memory upgrades? I was just looking at Newegg and Amazon for DDR4-2400 SODIMMS, but there are a variety of CAS latency timings available. Is there anything I should seek out or avoid?

Nothing specific - it’s a standard Raven ridge memory controller and should “just work” - I would say that in general, don’t go with anything smaller than whatever the machine comes with, and always buy the RAM in pairs to take advantage of dual channels. Anything over DDR4-2400 will simply be downclocked, but since 2666 laptop RAM is fairly cheap these days they would work just fine.

I ran a sister machine(t740) with a pair of 32GB DDR4-2666/CL18 (G.Skills Ripjaws), and it works just fine.

 

[patrick80]

Nothing specific - it’s a standard Raven ridge memory controller and should “just work” - I would say that in general, don’t go with anything smaller than whatever the machine comes with, and always buy the RAM in pairs to take advantage of dual channels. Anything over DDR4-2400 will simply be downclocked, but since 2666 laptop RAM is fairly cheap these days they would work just fine.

I ran a sister machine(t740) with a pair of 32GB DDR4-2666/CL18 (G.Skills Ripjaws), and it works just fine.

Thank you. I'll see if I can find anything reasonably priced. I've got a larger SSD on the way, and the t640 should be in my hands before the end of the week. I'm looking forward to having something new to tinker with.

I also see that the onboard ethernet controller is Realtek. Do you know if that will function with a fresh Ubuntu installation or if I have to do some more work to get it to work?

 

[patrick80]

Thank you. I'll see if I can find anything reasonably priced. I've got a larger SSD on the way, and the t640 should be in my hands before the end of the week. I'm looking forward to having something new to tinker with.

I also see that the onboard ethernet controller is Realtek. Do you know if that will function with a fresh Ubuntu installation or if I have to do some more work to get it to work?

To answer my own question, the Realtek ethernet works on a fresh install of Ubuntu server without additional configuration. I installed the OS first without having an ethernet cable plugged in and tried to configure the interface and DHCP client after the install, but after editing one config file without success, I gave up and reinstalled the OS with a network cable plugged in. This time the Ubuntu installer picked it up and automatically configured it for me.

Also, I saw earlier in the thread there was some speculation about NVMe drives working. I installed a 500gb NVMe drive and it works just fine. This is the one I used: https://www.amazon.com/gp/product/B07YFF3JCN/

 

[Hifihedgehog]

I've been using one of these as an HTPC for a while now and, for the most part, it works great.

One thing I didn't realize when I bought it, though, is that it only has DisplayPort 1.2 ports, which don't support HDR. As I'm currently experimenting with 4K HDR playback, this is a bummer.

Does anyone know anything about the HDMI Option Port add-on that is supposedly available for these systems? I can't seem to dig up any info on it (like, for example, the HDMI version or part number so I can determine if adding a native HDMI output would get me 4K HDR support).

Are you certain DisplayPort 1.4 is not working? I know that officially AMD supports DisplayPort 1.4 for the DisplayPort outputs on this processor line. What happened with first generation Raven Ridge like the 2400F is motherboard were only officially tested up to HDMI 1.4 but they still worked fine with HDMI 2.0 since the processor drives the monitor. I believe in some cases the motherboard manufacturers limited the output artificially in firmware but Linux drivers were set to bypass this firmware flag.

 

[Dave Corder]

Are you certain DisplayPort 1.4 is not working? I know that officially AMD supports DisplayPort 1.4 for the DisplayPort outputs on this processor line. What happened with first generation Raven Ridge like the 2400F is motherboard were only officially tested up to HDMI 1.4 but they still worked fine with HDMI 2.0 since the processor drives the monitor. I believe in some cases the motherboard manufacturers limited the output artificially in firmware but Linux drivers were set to bypass this firmware flag.

The official specs for this model specifically state "DisplayPort 1.2": HP t640 Thin Client Specifications | HP® Customer Support

However, it makes no mention of the HDMI version for the HDMI option port.

I played with it for a while and even installed the AMD driver package instead of letting Windows do its thing with drivers, but no luck. But, I'm also not sure I have a DP 1.4 to HDMI adapter (might only be DP 1.2). I might give a different adapter a try if you're fairly confident of might actually work...

 

[Hifihedgehog]

The official specs for this model specifically state "DisplayPort 1.2": HP t640 Thin Client Specifications | HP® Customer Support

However, it makes no mention of the HDMI version for the HDMI option port.

I played with it for a while and even installed the AMD driver package instead of letting Windows do its thing with drivers, but no luck. But, I'm also not sure I have a DP 1.4 to HDMI adapter (might only be DP 1.2). I might give a different adapter a try if you're fairly confident of might actually work...

I am not certain, so I would have to try this out first to give a definitive yes or no answer to this.

As a point of fact, Raven Ridge had a similar situation occur at launch which may also apply here which I personally had a hand in organizing a community effort to investigation. The Ryzen APUs then processor officially supported HDMI 2.0 but most motherboard makers for B350 and X370 only paid to be licensed up through HDMI 1.4. The end discovery was the motherboard made no difference since the processor was directly driving the signal. The motherboard makers had only paid for testing certification up through the older iteration but that in way limited support for HDMI 2.0z Only in the case of certain Linux distributions that explicitly read the BIOS tables to see what the official support level was was HDMI specification limited, which, in that case, was an artificial limitation since the hardware was more than up to the task. As memory serves me, those silly Linux limitations have since been lifted in the distribution driver packages.

Cutting to the chase, though, I am not sure if there is a global BIOS restriction in place here that would restrict DisplayPort 1.4 from occurring no matter what. The documentation from AMD clearly states the processor most definitely supports DisplayPort 1.4, but there is no telling how heavy-handed HP got in their design and if they are enforcing their advertised support level of DisplayPort aggressively or even at all.

The only way to truly find out is to test a DP 1.4 to HDMI 2.0 adapter that has HDR support and see if the HDR works or not. To that end, I am going to try this adapter out as soon as my unit comes in next week.

 

[Dave Corder]

I am not certain, so I would have to try this out first to give a definitive yes or no answer to this.

As a point of fact, Raven Ridge had a similar situation occur at launch which may also apply here which I personally had a hand in organizing a community effort to investigation. The Ryzen APUs then processor officially supported HDMI 2.0 but most motherboard makers for B350 and X370 only paid to be licensed up through HDMI 1.4. The end discovery was the motherboard made no difference since the processor was directly driving the signal. The motherboard makers had only paid for testing certification up through the older iteration but that in way limited support for HDMI 2.0z Only in the case of certain Linux distributions that explicitly read the BIOS tables to see what the official support level was was HDMI specification limited, which, in that case, was an artificial limitation since the hardware was more than up to the task. As memory serves me, those silly Linux limitations have since been lifted in the distribution driver packages.

Cutting to the chase, though, I am not sure if there is a global BIOS restriction in place here that would restrict DisplayPort 1.4 from occurring no matter what. The documentation from AMD clearly states the processor most definitely supports DisplayPort 1.4, but there is no telling how heavy-handed HP got in their design and if they are enforcing their advertised support level of DisplayPort aggressively or even at all.

The only way to truly find out is to test a DP 1.4 to HDMI 2.0 adapter that has HDR support and see if the HDR works or not. To that end, I am going to try this adapter out as soon as my unit comes in next week.

Hmm, interesting. I do recall seeing that the APU supports DP 1.4, but I've seen a handful of systems based on it that only claim to support DP 1.2.

I checked my Amazon order history and if I'm using the adapter I think I'm using, it's only DP 1.2 in the first place. So maybe that was my issue all along (though I seem to recall I couldn't get 1080p 30Hz HDR to work, which in theory should have based on bandwidth requirements, but I may be mis-remembering). I've ordered a couple of different adapters to try out (one adapter and one direct cable)...they should be here tomorrow so maybe I'll get a chance to test tomorrow night after the kids go to bed. I'll be very curious to see what happens for you and me...

 

[Dave Corder]

I am not certain, so I would have to try this out first to give a definitive yes or no answer to this.

As a point of fact, Raven Ridge had a similar situation occur at launch which may also apply here which I personally had a hand in organizing a community effort to investigation. The Ryzen APUs then processor officially supported HDMI 2.0 but most motherboard makers for B350 and X370 only paid to be licensed up through HDMI 1.4. The end discovery was the motherboard made no difference since the processor was directly driving the signal. The motherboard makers had only paid for testing certification up through the older iteration but that in way limited support for HDMI 2.0z Only in the case of certain Linux distributions that explicitly read the BIOS tables to see what the official support level was was HDMI specification limited, which, in that case, was an artificial limitation since the hardware was more than up to the task. As memory serves me, those silly Linux limitations have since been lifted in the distribution driver packages.

Cutting to the chase, though, I am not sure if there is a global BIOS restriction in place here that would restrict DisplayPort 1.4 from occurring no matter what. The documentation from AMD clearly states the processor most definitely supports DisplayPort 1.4, but there is no telling how heavy-handed HP got in their design and if they are enforcing their advertised support level of DisplayPort aggressively or even at all.

The only way to truly find out is to test a DP 1.4 to HDMI 2.0 adapter that has HDR support and see if the HDR works or not. To that end, I am going to try this adapter out as soon as my unit comes in next week.

Well I'll be damned, 4K HDR does seem to be working! I'm currently using this adapter: https://smile.amazon.com/gp/product/B077JB28KM/ and I am able to enable HDR in WIndows and I'm currently watching some 4k HDR content from my Plex server via Plex for Kodi and Kodi 19 with HDR enabled (confirmed to be direct playing). My TV lacks the ability to tell me if it's receiving HDR content, but it definitely looks different than what I'm used to! Playback is a bit stuttery still...I have some tweaking to do, but oh man am I a happy camper right now!

Edit: actually I just finally figured out how to see what kind of signal my tv is receiving, and it is indeed getting an HDR10 signal from my T640. Woot!

 

[Hifihedgehog]

Well I'll be ****, 4K HDR does seem to be working! I'm currently using this adapter: https://smile.amazon.com/gp/product/B077JB28KM/ and I am able to enable HDR in WIndows and I'm currently watching some 4k HDR content from my Plex server via Plex for Kodi and Kodi 19 with HDR enabled (confirmed to be direct playing). My TV lacks the ability to tell me if it's receiving HDR content, but it definitely looks different than what I'm used to! Playback is a bit stuttery still...I have some tweaking to do, but oh man am I a happy camper right now!

Edit: actually I just finally figured out how to see what kind of signal my tv is receiving, and it is indeed getting an HDR10 signal from my T640. Woot!

That's awesome and absolutely delightful news! I figured the DP certification may be a similar situation to the HDMI 2.0 certification fiasco with Ryzen 2000 APUs and the B350/X370 motherboards that I experienced first-hand in 2018. I'll be sure to pass this valuable bit of information along to some folks on Reddit who will be simply pleased as punch to hear this news. It's amazing to think what this little guy can do as a $100 HTPC.

 

[Dave Corder]

For anyone curious, these popped up on eBay recently and appear to be the miniDP and USB-C modules for the T640 and siblings (based on my visual estimation, anyway):

• HP mDP Option Card mini Display Board Module L42735-001 L42734-001
• HP USB Type C OPTION CARD L42726-000 L42725-001

Although interior shots I've seen of the T640 show another cable from the main board to the USB-C option card that isn't mentioned in the auction. I'm still waiting for the HDMI option board to surface...

 

[WANg]

For anyone curious, these popped up on eBay recently and appear to be the miniDP and USB-C modules for the T640 and siblings (based on my visual estimation, anyway):

• HP mDP Option Card mini Display Board Module L42735-001 L42734-001
• HP USB Type C OPTION CARD L42726-000 L42725-001

Although interior shots I've seen of the T640 show another cable from the main board to the USB-C option card that isn't mentioned in the auction. I'm still waiting for the HDMI option board to surface...

Hmmm...note that on the mDP card there is a reference to "Tranquil", which is the HP internal codename for the t640 thin client. The USB-C card references Psyduck, which might be the codename for the t540 (I missed out on a CDW outlet deal on one). My educated guess says that the connector might simply reuse the HP FlexIO options on the HP EliteDesk 705 G4 (Raven Ridge Ryzen+) TinyMiniMicro machines...except they moved a single screwhole a few mm to the north just to fit the form factor on the EliteDesk. The t540 has the same connector as the t640 and can definitely use the part. Note that L42726-000 L42725-001 is indeed the USB-C adapter, and that 10 pin cable is used for USB-PD. Yes...you can power the thin client using that port as long as your power brick can do PD45 (15v x 3w) and you have the 10 pin cable connect to the white port next to the NVMe slot.

 

[Dave Corder]

Is anyone else using these little guys as HTPCs? I'm having an audio issue I can't wrap my head around yet.

I seem to be having an issue where I can't passthrough Dolby TrueHD or DTS-HD MA to my receivers. I have two of them, in two wildly different setups (different receivers, different DP to HDMI adapters, different displays, one even has a 4K switch and 4K->1080p downconverter in the display chain), but both receivers are fully capable of those codecs over HDMI (and one used to work with my old HTPC with discrete Nvidia graphics). Both setups seem to do just fine with vanilla Dolby Digital and DTS, just not the TrueHD or DTS-HD MA variants, at least with Plex Media Player and Plex HTPC.

I haven't had much time to investigate, though...could just be Plex, or could just be a limitation of DP to HDMI or something. Was just wondering if anyone else had come across this or could give me some pointers before I dig in myself.

 

[Hifihedgehog]

Is anyone else using these little guys as HTPCs? I'm having an audio issue I can't wrap my head around yet.

I seem to be having an issue where I can't passthrough Dolby TrueHD or DTS-HD MA to my receivers. I have two of them, in two wildly different setups (different receivers, different DP to HDMI adapters, different displays, one even has a 4K switch and 4K->1080p downconverter in the display chain), but both receivers are fully capable of those codecs over HDMI (and one used to work with my old HTPC with discrete Nvidia graphics). Both setups seem to do just fine with vanilla Dolby Digital and DTS, just not the TrueHD or DTS-HD MA variants, at least with Plex Media Player and Plex HTPC.

I haven't had much time to investigate, though...could just be Plex, or could just be a limitation of DP to HDMI or something. Was just wondering if anyone else had come across this or could give me some pointers before I dig in myself.

Not sure. It "just works" plugged in directly to the receiver via (1) a DP to HDMI adapter and (2) an HDMI cable. Try isolating by removing the downconverters and switches since those can introduce issues.

 

[Dave Corder]

Not sure. It "just works" plugged in directly to the receiver via (1) a DP to HDMI adapter and (2) an HDMI cable. Try isolating by removing the downconverters and switches since those can introduce issues.

I have one plugged straight into a receiver, and it has the same problem.

I've done a little bit more research, and it may be that (most?) active DP to HDMI adapters don't support the high-res audio formats in their conversion chips. I think both of my setups have active adapters - I know the one with the 4K TV does because I needed an active adapter to get 4K HDR. Not sure what I ended up using for the other one that only has a 1080p projector hooked up to it - I'll have to go look at the cabling later today.

I've also ordered a couple of supposedly-passive adapters to try out as well to see if that changes anything.

 

[Dave Corder]

So it turns out that my audio issues were indeed due to my active DP to HDMI adapters, and I learned a bit more about DisplayPort. I swapped the active adapters in both my setups with different, passive adapters and they work beautifully in both (I even still get 4k30 + HDR even going through a 4K HDMI switch and 4K HDMI splitter) and I can pass through DTS-MA and TrueHD audio to both receivers without a hitch.

The ports on the T640 are "DP++" or "dual-mode DisplayPort" outputs. For those who don't know, that means that they can output a native DP or native HDMI signal depending on what's connected to it. So you can use a passive DP to HDMI adapter to get an HDMI connection to your display and sound device(s) of choice. And this is a normal HDMI connection that can do all the normal HDMI stuff, like bitstream a bajillion different audio formats and support 4k30 + HDR. (The adapters I used: Plugable DisplayPort to HDMI Passive Adapter [this is the one that I am using for 4k30 HDR] and 4K DisplayPort to HDMI Adapter Cable, WARRKY ( 2K 60Hz, 1080p 120Hz) Uni-Directional High-Speed DP PC to HDMI Monitor Converter)

If you use an active adapter, though, there's a chip in it that's actually taking the DP signal and converting it to HDMI for you, and either DP itself doesn't support DTS-MA and TrueHD, or the converter chip doesn't support them, but whichever is the case, you can't pass through those formats to a receiver. At least not with the adapters I was using (Active DisplayPort to HDMI Cable 4K@60Hz HDR, CableCreation 8FT Unidirectional DisplayPort to HDMI Monitor Cable, and Active DisplayPort to HDMI Adapter, BENFEI 4K DisplayPort to HDMI Active Adapter).

So after all the hoops I jumped through initially in the first place to get HDR working on one of my T640s earlier in this thread, it turns out I was really going about it the wrong way in the first place and should have gone with passive adapters instead of adapters all along. Live and learn. And three cheers for the T640

 

[Reshesnik]

Fun fact: these are Windows 11 compatible. Ran the checker tool (all green), then updated it with no issues.

 

[WANg]

Fun fact: these are Windows 11 compatible. Ran the checker tool (all green), then updated it with no issues.

They are! AFAIK the t640s are like Athlon 300Us or something in that ballpark, which makes them Win11 kosher. I only wish they are back at the 120 dollar pricepoint of early Q2 ‘20.

 

[Badharrow]

Hey guys, am I missing something, I see these regularly advertised for 1000 aud, no where near the 150 usd talked about at the start of the post. It has me really intrigued though, love the form factor and h.265.

Thanks

 

[WANg]

Hey guys, am I missing something, I see these regularly advertised for 1000 aud, no where near the 150 usd talked about at the start of the post. It has me really intrigued though, love the form factor and h.265.

Thanks

You missed the big sale stateside at the beginning of 2021 and its associated thread.
The pricing on the t640 is around 225 these days on eBay US - much less attractive at that price point, but some are known to be offered and purchased cheaper though.