Both firms have unveiled 84-inch screens featuring the latest technologically wizardry intended to entice customers into shelling out on new sets, with Sony's Bravia version slated for a UK release this autumn.
The two 4k LCD sets have high resolutions of 3840 x 2160. 4K is not necessarily new, but Sony has decided to market its mammoth TV around its increased resolution, making less noise about its 3D capabilities.
The price tag is likely to be suitably astronomical when the first devices hit the UK later this year.
So are Sony and Toshiba onto a money spinner that will help the beleaguered TV business? Hardware retailers could certainly do with a new gimmick to spur on sales in a way that 3D has failed to achieve on a large scale.
Nigh on all TV vendors are operating at losses, and most have been for some time - even the seemingly unstoppable Samsung has been struggling with its TV sales. Part of the reason is that consumers in markets such as the UK have, in many cases, already upgraded to flat screen LCDs, so replacement sales remain slow.
According to display market analyst, Bob Raikes, who is present at IFA, the superlative technology should firmly grasp the attention of gamers and film buffs, but mass market appeal could be hampered by difficulties in receiving 4K signals
"4K will not be a big driver of purchases for watching broadcast content because of the barriers to transmissions," Raikes said, speaking with TechEye. "Even carriers that have plenty of bandwidth will need new set top boxes and transmission equipment and the new generation of codecs such as the new H.264 HEVC will need time to mature and be built into lower cost chips."
However, Raikes points out that Toshiba is already showing some 4K game content from PCs using native 4K content at IFA, and describes them as "simply stunning".
"The feeling is so immersive that I found I was getting genuine motion sickness watching a driving game," Raikes said.
He added that using Blu-ray discs using content shot on 4K cameras works well when upscaled onto 4K sets.
"So, Sony is probably thinking more about Blu-ray and the next generation PlayStation," he said, adding "if that ran at 4K natively, I'd be very tempted to upgrade my TV".
DisplaySeach analyst Paul Gray, also at IFA, highlights one of the of the major drawbacks with 4K at this time - the lack of available content - and he does not anticipate 4k sets seeing major sales, at least in the short term.
"We do not anticipate them tunneling rapidly down the product ranges," Gray said. "The critical issue is no content in 4k2k at present. If the PC industry starts a pixel war (Apple are already increasing Mac resolutions) and the next generation of games machines have higher resolutions then they could catalyse growth."
"However there are some unsolved steps in panel technology that need to be fixed first. For example, 4k2k displays currently have a limit on refresh at 120Hz," Gray said.