There are three different versions of the AMD Navi 14 desktop GPU in the pipeline, according to a recent Linux driver patch. The patch adds in peak clock figures for both mobile and desktop versions of the Navi 14 GPU, though what Linux refers to as ‘peak clock’ AMD is now classing as ‘Game Clock.’
The Navi 14 chip is going to be the beating silicon heart of the AMD RX 5500 series of graphics cards, but we had assumed there would only be two different GPUs in the range – an RX 5500 and an RX 5500 XT. Both have appeared in GPU listings from AMD’s graphics card partners, with no mention of a third option… which could mean that Navi 14 is also going to be fitted into an RX 5300 form too.
The other interesting thing is that the way the chips are designated seems to suggest that despite the full Navi 14 GPU seemingly containing 24 compute units and a potential 1,536 RDNA cores, the top-end RX 5500 XT might actually just have the 22 CUs AMD has previously listed for the RX 5500-series.
The images and expected layout of the Navi 14 GPU suggests that the RX 5500-series cards aren’t going to come sporting the full graphics core. AMD has so far only referenced the series coming with 22 CUs, 1,408 RDNA cores, and a Game Clock of up to 1,717MHz.
The listing in the Linux code (via Videocardz) suggests that 1,717MHz part will be the Navi 14 XTX, and if AMD’s Navi 10 precedence holds true that will be the top card, and therefore the RX 5500 XT. The RX 5500 XT would then be a 1,408 core card, which is kinda disappointing.
The Linux patch, with the key lines listed below, also highlights the Game Clock of two distinct versions of the Navi 14 mobile part, the XTM and XLM.
add navi14 umd pstate peak clock support.
NAVI14_UMD_PSTATE_PEAK_XT_GFXCLK 1670 MHz
NAVI14_UMD_PSTATE_PEAK_XTM_GFXCLK 1448 MHz
NAVI14_UMD_PSTATE_PEAK_XLM_GFXCLK 1181 MHz
NAVI14_UMD_PSTATE_PEAK_XTX_GFXCLK 1717 MHz
NAVI14_UMD_PSTATE_PEAK_XL_GFXCLK 1448 MHz
That would leave the touted Navi 14 XT at 1,670MHz as the straight RX 5500, potentially with the same core count and just different levels of memory. What then is the Navi 14 XL?
The expectation is that the lower-spec chip might end up powering the unannounced RX 5300-series, though I’m not 100% convinced of that. It’s possible AMD is planning on giving each RX 5500-series card the same basic core configuration, but with the clock speed and memory subsystem changing between them.
My guess would be an RX 5500 XT with 8GB of GDDR6 at 1,717MHz, and maybe two RX 5500 cards with 4GB GDDR6 at 1,670MHz and 4GB GDDR5 at 1,448MHz respectively.
But the RX 5500-series announcement and ‘launch’ has been rather bizarre anyways, so I also wouldn’t be surprised if this all referenced something else entirely. Maybe a watch. A Navi 14 watch.