Overclock.net › Forums › Industry News › Hardware News › [Lenovo VP/AVForums] Lenovo set to release 4k TV powered by Nvidia Tegra K1
New Posts  All Forums:Forum Nav:

[Lenovo VP/AVForums] Lenovo set to release 4k TV powered by Nvidia Tegra K1 - Page 2

post #11 of 31
Quote:
Originally Posted by Majin SSJ Eric View Post

Can we please just get a 4k TV with DP connections for 60Hz??? Only thing stopping me from using one as a monitor...

Panasonic TC-L65WT600
Quote:
Originally Posted by t00sl0w View Post

how about a 4K TV on anything except a LCD panel?
i want good PQ, color depth, and contrast alongside the resolution.

LG is set to launch a 4K OLED TV in Q2 2014 so we're almost there: [OLED-Info]LG 77EC9800 Looks like it'll be running webOS too. Double awesome!
     
CPUMotherboardGraphicsRAM
Intel Core i7 4930K @ 4.2Ghz (42x100) 1.21V ASUS Rampage IV Extreme 2x3GB MSI Radeon HD 7970 OC @ 1075Mhz/6100 4x4GB G.SKILL ARES DDR3-1866 (Blue) 
Hard DriveHard DriveOptical DriveOptical Drive
2x256GB Crucial M4 (RAID 0) 2x3TB Seagate Barracuda 7200.14 (RAID 1) 12X Samsung SH-B123L/BSBP BD Combo 2.4X Toshiba SD-H802A HD DVD-ROM (IDE) 
CoolingOSMonitorKeyboard
Cooler Master TPC-812 w/ Dual Gentle Typhoon AP15 Windows 10 Pro 64 bit 21" NEC AccuSync 120 (CRT) Ducky DK9008G2-BELLB (Cherry MX Brown) 
PowerCaseMouseMouse Pad
750W EVGA SuperNOVA NEX750B NZXT Switch 810 (Black) Razer Boomer Speed (Ball) Razer Goliathus 
AudioOther
FiiO E10 1.5kVA APC J35B Power Conditioner/UPS 
CPUMotherboardGraphicsRAM
Dual Xeon X5650 @ 3.9Ghz (195x20) 1.3375V EVGA Classified SR-2 1280MB EVGA GeForce GTX 470 6x4GB Team Group Xtreem Dark DDR3-1600 
Hard DriveCoolingOSPower
160GB Intel 320 XSPC RayStorm | Danger Den DD-GTX470 | Swiftech... Ubuntu 14.10 64 bit 1000W Antec CP (CPX) 
Case
XIGMATEK ELYSIUM (Black) 
  hide details  
Reply
     
CPUMotherboardGraphicsRAM
Intel Core i7 4930K @ 4.2Ghz (42x100) 1.21V ASUS Rampage IV Extreme 2x3GB MSI Radeon HD 7970 OC @ 1075Mhz/6100 4x4GB G.SKILL ARES DDR3-1866 (Blue) 
Hard DriveHard DriveOptical DriveOptical Drive
2x256GB Crucial M4 (RAID 0) 2x3TB Seagate Barracuda 7200.14 (RAID 1) 12X Samsung SH-B123L/BSBP BD Combo 2.4X Toshiba SD-H802A HD DVD-ROM (IDE) 
CoolingOSMonitorKeyboard
Cooler Master TPC-812 w/ Dual Gentle Typhoon AP15 Windows 10 Pro 64 bit 21" NEC AccuSync 120 (CRT) Ducky DK9008G2-BELLB (Cherry MX Brown) 
PowerCaseMouseMouse Pad
750W EVGA SuperNOVA NEX750B NZXT Switch 810 (Black) Razer Boomer Speed (Ball) Razer Goliathus 
AudioOther
FiiO E10 1.5kVA APC J35B Power Conditioner/UPS 
CPUMotherboardGraphicsRAM
Dual Xeon X5650 @ 3.9Ghz (195x20) 1.3375V EVGA Classified SR-2 1280MB EVGA GeForce GTX 470 6x4GB Team Group Xtreem Dark DDR3-1600 
Hard DriveCoolingOSPower
160GB Intel 320 XSPC RayStorm | Danger Den DD-GTX470 | Swiftech... Ubuntu 14.10 64 bit 1000W Antec CP (CPX) 
Case
XIGMATEK ELYSIUM (Black) 
  hide details  
Reply
post #12 of 31
Quote:
Originally Posted by t00sl0w View Post

how about a 4K TV on anything except a LCD panel?
i want good PQ, color depth, and contrast alongside the resolution.

you forgot black level, no clouding and motion resolution too..
post #13 of 31
Quote:
Originally Posted by Zero4549 View Post

People have collectively moved away from plasma for several reasons.

Several bad reasons really. Most of which are just mis-information perpetuated by LCD manufacturers and ignorant end users. Plasma is still far superior to LCD tech. I would love to see a 4K plasma TV, and once cheaper a 4K OLED
Gaming
(17 items)
 
Gaming PC
(20 items)
 
 
CPUMotherboardGraphicsRAM
7700K AS Rock Z170 OC Formula Titan X Pascal 2050MHz 64GB DDR4-3200 14-14-14-34-1T 
Hard DriveHard DriveHard DriveCooling
950 EVO m.2 OS drive 850 EVO 1TB games drive Intel 730 series 500GB games drive Custom water cooling 
OSMonitorKeyboardPower
Win 10 Pro x64 AMH A399U E-Element mechanical, black switches, Vortex b... EVGA G3 1kw 
CaseMouseAudioAudio
Lian-Li PC-V1000L Redragon M901 LH Labs Pulse X Infinity DAC Custom built balanced tube amp with SS diamond ... 
Audio
MrSpeakers Alpha Prime 
  hide details  
Reply
Gaming
(17 items)
 
Gaming PC
(20 items)
 
 
CPUMotherboardGraphicsRAM
7700K AS Rock Z170 OC Formula Titan X Pascal 2050MHz 64GB DDR4-3200 14-14-14-34-1T 
Hard DriveHard DriveHard DriveCooling
950 EVO m.2 OS drive 850 EVO 1TB games drive Intel 730 series 500GB games drive Custom water cooling 
OSMonitorKeyboardPower
Win 10 Pro x64 AMH A399U E-Element mechanical, black switches, Vortex b... EVGA G3 1kw 
CaseMouseAudioAudio
Lian-Li PC-V1000L Redragon M901 LH Labs Pulse X Infinity DAC Custom built balanced tube amp with SS diamond ... 
Audio
MrSpeakers Alpha Prime 
  hide details  
Reply
post #14 of 31
Yeah, I just got a cheap 60" plasma from WM in Jan and it has been amazing so far...
post #15 of 31
The general public doesn't want hot, power guzzling, bulky TVs with a reputation for image burn in and retention. Can you really blame them?
Arcane
(33 items)
 
Sanctum
(9 items)
 
Fukurou
(15 items)
 
CPUMotherboardGraphicsGraphics
Core i7 980x GIGABYTE GA-EX58-UD5 MSI RX 480 GAMING X 4GB MSI GeForce GTX 680 Lightning 
RAMHard DriveHard DriveHard Drive
Kingston HyperX T1 Intel X25-M WD Caviar Black FASS Plextor M5S 
Hard DriveHard DriveOptical DriveOptical Drive
WD Velociraptor WD Caviar Black FALS Sony DVD Burner w/ Lightscribe LG Bluray + HDDVD 
CoolingCoolingCoolingOS
Black Ice GTX 360 Black Ice GTX 240 Panaflo High Speed - Push-Pull w/ shrouds Windows 7 Pro (64) 
OSMonitorMonitorKeyboard
Ubuntu (64) X-Star DP2710 ASUS VK266H Black 25.5" 2ms LCD X-Armor U9BL (Mech) 
PowerCaseMouseMouse Pad
EVGA 1000 P2 Cooler Master HAF 932 Razer Deathadder Chroma Cougar Control 
AudioAudioAudioAudio
ATH-A900X Maudio AV-40 Polk PSW-10 Zalman Mic-1 (Clip-on Mic) 
AudioOtherOtherOther
Sound Blaster X7 LE Logitech G13 Wacom Intuos 3 Scythe "3-Foot Switch" 
Other
Modded PS4, PS3, Xbox 360, and Logitech PC Cont... 
CPUMotherboardGraphicsRAM
Ryzen 7 1700 MSI B350M Mortar Arctic RX Vega 64 G.Skill TridentZ  
Hard DriveHard DriveOSPower
Samsung EVO 960 Consatellation Windows 10 Pro Corsair HX 1050 
Case
Raijintek Aeneas White Window 
CPUMotherboardRAMHard Drive
Core i5-661 GA-H55-USB3 12GB DDR3 1333 WD Caviar Black AALS 640GB 
Hard DriveHard DriveOptical DriveCooling
WD Caviar Green EARS 2TB Vertex Turbo 60GB (SSD) Samsung Blu-ray, Samsung DVD Burner H50 (With push/pull nocturas) 
OSMonitorKeyboardPower
Windows 10 Professional 64 LG 47inch LED LCD Saitek Eclipse Lite-touch Wireless Seasonic X750 Gold 
CaseAudio
CM690 II Passive bookshelfspeakers + amp. 
  hide details  
Reply
Arcane
(33 items)
 
Sanctum
(9 items)
 
Fukurou
(15 items)
 
CPUMotherboardGraphicsGraphics
Core i7 980x GIGABYTE GA-EX58-UD5 MSI RX 480 GAMING X 4GB MSI GeForce GTX 680 Lightning 
RAMHard DriveHard DriveHard Drive
Kingston HyperX T1 Intel X25-M WD Caviar Black FASS Plextor M5S 
Hard DriveHard DriveOptical DriveOptical Drive
WD Velociraptor WD Caviar Black FALS Sony DVD Burner w/ Lightscribe LG Bluray + HDDVD 
CoolingCoolingCoolingOS
Black Ice GTX 360 Black Ice GTX 240 Panaflo High Speed - Push-Pull w/ shrouds Windows 7 Pro (64) 
OSMonitorMonitorKeyboard
Ubuntu (64) X-Star DP2710 ASUS VK266H Black 25.5" 2ms LCD X-Armor U9BL (Mech) 
PowerCaseMouseMouse Pad
EVGA 1000 P2 Cooler Master HAF 932 Razer Deathadder Chroma Cougar Control 
AudioAudioAudioAudio
ATH-A900X Maudio AV-40 Polk PSW-10 Zalman Mic-1 (Clip-on Mic) 
AudioOtherOtherOther
Sound Blaster X7 LE Logitech G13 Wacom Intuos 3 Scythe "3-Foot Switch" 
Other
Modded PS4, PS3, Xbox 360, and Logitech PC Cont... 
CPUMotherboardGraphicsRAM
Ryzen 7 1700 MSI B350M Mortar Arctic RX Vega 64 G.Skill TridentZ  
Hard DriveHard DriveOSPower
Samsung EVO 960 Consatellation Windows 10 Pro Corsair HX 1050 
Case
Raijintek Aeneas White Window 
CPUMotherboardRAMHard Drive
Core i5-661 GA-H55-USB3 12GB DDR3 1333 WD Caviar Black AALS 640GB 
Hard DriveHard DriveOptical DriveCooling
WD Caviar Green EARS 2TB Vertex Turbo 60GB (SSD) Samsung Blu-ray, Samsung DVD Burner H50 (With push/pull nocturas) 
OSMonitorKeyboardPower
Windows 10 Professional 64 LG 47inch LED LCD Saitek Eclipse Lite-touch Wireless Seasonic X750 Gold 
CaseAudio
CM690 II Passive bookshelfspeakers + amp. 
  hide details  
Reply
post #16 of 31
Quote:
Originally Posted by phill1978 View Post

you forgot black level, no clouding and motion resolution too..

that i did and i cant believe it as its one of the most important things.
black level is one thing, but its insane how many LCD guys arent aware of the massive motion blur their sets have, its actually distracting.

Quote:
Originally Posted by EniGma1987 View Post

Several bad reasons really. Most of which are just mis-information perpetuated by LCD manufacturers and ignorant end users. Plasma is still far superior to LCD tech. I would love to see a 4K plasma TV, and once cheaper a 4K OLED

thank you, 2013 models from panasonic for one have completely removed all the "bad" plasma things that people used to spout about, like image retention, power and heat. my panny plasma actually runs cooler than my dads brand new quattron or whatever that goofy line was called.
Quote:
Originally Posted by Zero4549 View Post

The general public doesn't want hot, power guzzling, bulky TVs with a reputation for image burn in and retention. Can you really blame them?

those are really old arguments against plasmas that dont hold any lights against modern ones. maybe in 2006 that was a valid argument, but in 2014 it isnt.
plasmas are cooler, they dont suck energy anymore and they do not have image retention problems. you would have to really try hard at getting IR to have it happen on a modern set.
the other arguments became marketing terms used by LCD pushers.
Quote:
Originally Posted by Assimilator87 View Post

Panasonic TC-L65WT600
LG is set to launch a 4K OLED TV in Q2 2014 so we're almost there: [OLED-Info]LG 77EC9800 Looks like it'll be running webOS too. Double awesome!

that is very nice, we need something to replace plasma and OLED looks to be the only option, these sets need to start coming out now!
wonder if LG is going to break webOS or actually use its strong points.
new life
(17 items)
 
Ripley
(6 items)
 
 
CPUMotherboardGraphicsRAM
3820 @ 4.3giggles sabertooth x79 EVGA gtx 970 @ working on OC mushkin redline 16gb @ 1866 c9  
Hard DriveHard DriveHard DriveHard Drive
crucial m4 128gb WD blue 1tb hitachi deskstar 500gb WD Black 2tb 
Hard DriveOptical DriveCoolingOS
Hitachi Desktar NAS 6tb LG Bluray royale with cheese seidon 240m win 10 x64 
MonitorKeyboardPowerCase
acer G245HDL x2 logitech g710+ corsair 650w switch 810 white 
Mouse
rat 7 
CPUGraphicsRAMHard Drive
i5-4200u HD 4400 8gb @ 1600mhz Crucial MX300 275gb 
OSMonitor
Manjaro 15.6" 1080p 
  hide details  
Reply
new life
(17 items)
 
Ripley
(6 items)
 
 
CPUMotherboardGraphicsRAM
3820 @ 4.3giggles sabertooth x79 EVGA gtx 970 @ working on OC mushkin redline 16gb @ 1866 c9  
Hard DriveHard DriveHard DriveHard Drive
crucial m4 128gb WD blue 1tb hitachi deskstar 500gb WD Black 2tb 
Hard DriveOptical DriveCoolingOS
Hitachi Desktar NAS 6tb LG Bluray royale with cheese seidon 240m win 10 x64 
MonitorKeyboardPowerCase
acer G245HDL x2 logitech g710+ corsair 650w switch 810 white 
Mouse
rat 7 
CPUGraphicsRAMHard Drive
i5-4200u HD 4400 8gb @ 1600mhz Crucial MX300 275gb 
OSMonitor
Manjaro 15.6" 1080p 
  hide details  
Reply
post #17 of 31
Quote:
Originally Posted by t00sl0w View Post

that i did and i cant believe it as its one of the most important things.
black level is one thing, but its insane how many LCD guys arent aware of the massive motion blur their sets have, its actually distracting.
thank you, 2013 models from panasonic for one have completely removed all the "bad" plasma things that people used to spout about, like image retention, power and heat. my panny plasma actually runs cooler than my dads brand new quattron or whatever that goofy line was called.
those are really old arguments against plasmas that dont hold any lights against modern ones. maybe in 2006 that was a valid argument, but in 2014 it isnt.
plasmas are cooler, they dont suck energy anymore and they do not have image retention problems. you would have to really try hard at getting IR to have it happen on a modern set.
the other arguments became marketing terms used by LCD pushers.
that is very nice, we need something to replace plasma and OLED looks to be the only option, these sets need to start coming out now!
wonder if LG is going to break webOS or actually use its strong points.

Plasmas are still, and will always be less power/heat efficient than LCDs. Yes, they are improved compared to years ago, but they still aren't even in the same ballpark as an LCD. Image retention and burn in still exist, and although with "intended usage" it is no longer a serious concern, it can be easily achieved with improper usage. Plasmas are still larger and heavier than LCDs.

Your level of acceptable isn't the same as everyone else's.

Personally I have a computer with 60+ decibel fans running 24/7 in my bedroom, but I don't try to tell other people that they shouldn't value low noise computers.
Arcane
(33 items)
 
Sanctum
(9 items)
 
Fukurou
(15 items)
 
CPUMotherboardGraphicsGraphics
Core i7 980x GIGABYTE GA-EX58-UD5 MSI RX 480 GAMING X 4GB MSI GeForce GTX 680 Lightning 
RAMHard DriveHard DriveHard Drive
Kingston HyperX T1 Intel X25-M WD Caviar Black FASS Plextor M5S 
Hard DriveHard DriveOptical DriveOptical Drive
WD Velociraptor WD Caviar Black FALS Sony DVD Burner w/ Lightscribe LG Bluray + HDDVD 
CoolingCoolingCoolingOS
Black Ice GTX 360 Black Ice GTX 240 Panaflo High Speed - Push-Pull w/ shrouds Windows 7 Pro (64) 
OSMonitorMonitorKeyboard
Ubuntu (64) X-Star DP2710 ASUS VK266H Black 25.5" 2ms LCD X-Armor U9BL (Mech) 
PowerCaseMouseMouse Pad
EVGA 1000 P2 Cooler Master HAF 932 Razer Deathadder Chroma Cougar Control 
AudioAudioAudioAudio
ATH-A900X Maudio AV-40 Polk PSW-10 Zalman Mic-1 (Clip-on Mic) 
AudioOtherOtherOther
Sound Blaster X7 LE Logitech G13 Wacom Intuos 3 Scythe "3-Foot Switch" 
Other
Modded PS4, PS3, Xbox 360, and Logitech PC Cont... 
CPUMotherboardGraphicsRAM
Ryzen 7 1700 MSI B350M Mortar Arctic RX Vega 64 G.Skill TridentZ  
Hard DriveHard DriveOSPower
Samsung EVO 960 Consatellation Windows 10 Pro Corsair HX 1050 
Case
Raijintek Aeneas White Window 
CPUMotherboardRAMHard Drive
Core i5-661 GA-H55-USB3 12GB DDR3 1333 WD Caviar Black AALS 640GB 
Hard DriveHard DriveOptical DriveCooling
WD Caviar Green EARS 2TB Vertex Turbo 60GB (SSD) Samsung Blu-ray, Samsung DVD Burner H50 (With push/pull nocturas) 
OSMonitorKeyboardPower
Windows 10 Professional 64 LG 47inch LED LCD Saitek Eclipse Lite-touch Wireless Seasonic X750 Gold 
CaseAudio
CM690 II Passive bookshelfspeakers + amp. 
  hide details  
Reply
Arcane
(33 items)
 
Sanctum
(9 items)
 
Fukurou
(15 items)
 
CPUMotherboardGraphicsGraphics
Core i7 980x GIGABYTE GA-EX58-UD5 MSI RX 480 GAMING X 4GB MSI GeForce GTX 680 Lightning 
RAMHard DriveHard DriveHard Drive
Kingston HyperX T1 Intel X25-M WD Caviar Black FASS Plextor M5S 
Hard DriveHard DriveOptical DriveOptical Drive
WD Velociraptor WD Caviar Black FALS Sony DVD Burner w/ Lightscribe LG Bluray + HDDVD 
CoolingCoolingCoolingOS
Black Ice GTX 360 Black Ice GTX 240 Panaflo High Speed - Push-Pull w/ shrouds Windows 7 Pro (64) 
OSMonitorMonitorKeyboard
Ubuntu (64) X-Star DP2710 ASUS VK266H Black 25.5" 2ms LCD X-Armor U9BL (Mech) 
PowerCaseMouseMouse Pad
EVGA 1000 P2 Cooler Master HAF 932 Razer Deathadder Chroma Cougar Control 
AudioAudioAudioAudio
ATH-A900X Maudio AV-40 Polk PSW-10 Zalman Mic-1 (Clip-on Mic) 
AudioOtherOtherOther
Sound Blaster X7 LE Logitech G13 Wacom Intuos 3 Scythe "3-Foot Switch" 
Other
Modded PS4, PS3, Xbox 360, and Logitech PC Cont... 
CPUMotherboardGraphicsRAM
Ryzen 7 1700 MSI B350M Mortar Arctic RX Vega 64 G.Skill TridentZ  
Hard DriveHard DriveOSPower
Samsung EVO 960 Consatellation Windows 10 Pro Corsair HX 1050 
Case
Raijintek Aeneas White Window 
CPUMotherboardRAMHard Drive
Core i5-661 GA-H55-USB3 12GB DDR3 1333 WD Caviar Black AALS 640GB 
Hard DriveHard DriveOptical DriveCooling
WD Caviar Green EARS 2TB Vertex Turbo 60GB (SSD) Samsung Blu-ray, Samsung DVD Burner H50 (With push/pull nocturas) 
OSMonitorKeyboardPower
Windows 10 Professional 64 LG 47inch LED LCD Saitek Eclipse Lite-touch Wireless Seasonic X750 Gold 
CaseAudio
CM690 II Passive bookshelfspeakers + amp. 
  hide details  
Reply
post #18 of 31
Quote:
Originally Posted by Zero4549 View Post

Plasmas are still, and will always be less power/heat efficient than LCDs. Yes, they are improved compared to years ago, but they still aren't even in the same ballpark as an LCD. Image retention and burn in still exist, and although with "intended usage" it is no longer a serious concern, it can be easily achieved with improper usage. Plasmas are still larger and heavier than LCDs.

Your level of acceptable isn't the same as everyone else's.

Personally I have a computer with 60+ decibel fans running 24/7 in my bedroom, but I don't try to tell other people that they shouldn't value low noise computers.

you are right, i give up some "ease of use" with my plasma's when it comes to something like pausing a movie or navigating a menu on something like my roku when i leave the room...sure, IR is almost nonexistant nowadays but my wife and i are sure to either change the channel or toss up the screen wipe if we intend to be gone for minutes or longer.
but the superb image quality is worth it in my eyes.
the weight though is the biggest pain in the izzy with plasma's...been wanting to wall mount, but finding one intended for anything other than LCDs is hard, and i have a 60" and a 50" so both are heavy.

side note, i am a fellow member in the camp of jet engine PCs...all of my fans run off the molex adapters, haha...100% power! and i have 6 case fans alone, not counting the 2 on my rad and the 2 on my GPU which i have idling at 50%.
noise doesnt bother me, i want cold...and i use headphones.
new life
(17 items)
 
Ripley
(6 items)
 
 
CPUMotherboardGraphicsRAM
3820 @ 4.3giggles sabertooth x79 EVGA gtx 970 @ working on OC mushkin redline 16gb @ 1866 c9  
Hard DriveHard DriveHard DriveHard Drive
crucial m4 128gb WD blue 1tb hitachi deskstar 500gb WD Black 2tb 
Hard DriveOptical DriveCoolingOS
Hitachi Desktar NAS 6tb LG Bluray royale with cheese seidon 240m win 10 x64 
MonitorKeyboardPowerCase
acer G245HDL x2 logitech g710+ corsair 650w switch 810 white 
Mouse
rat 7 
CPUGraphicsRAMHard Drive
i5-4200u HD 4400 8gb @ 1600mhz Crucial MX300 275gb 
OSMonitor
Manjaro 15.6" 1080p 
  hide details  
Reply
new life
(17 items)
 
Ripley
(6 items)
 
 
CPUMotherboardGraphicsRAM
3820 @ 4.3giggles sabertooth x79 EVGA gtx 970 @ working on OC mushkin redline 16gb @ 1866 c9  
Hard DriveHard DriveHard DriveHard Drive
crucial m4 128gb WD blue 1tb hitachi deskstar 500gb WD Black 2tb 
Hard DriveOptical DriveCoolingOS
Hitachi Desktar NAS 6tb LG Bluray royale with cheese seidon 240m win 10 x64 
MonitorKeyboardPowerCase
acer G245HDL x2 logitech g710+ corsair 650w switch 810 white 
Mouse
rat 7 
CPUGraphicsRAMHard Drive
i5-4200u HD 4400 8gb @ 1600mhz Crucial MX300 275gb 
OSMonitor
Manjaro 15.6" 1080p 
  hide details  
Reply
post #19 of 31
Yeah, my 60" LG plasma is very heavy but I don't have any desire to wall mount it. I also don't even worry about static images on screen. Any IR is gone within a few minutes of normal viewing and tbh, permanent IR is almost impossible with today's plasma's...
post #20 of 31
contrast alongside the resolution.gDKQOr
Edited by theorydo - 3/17/14 at 8:25pm
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Hardware News
Overclock.net › Forums › Industry News › Hardware News › [Lenovo VP/AVForums] Lenovo set to release 4k TV powered by Nvidia Tegra K1